NUTRITIONAL STATUS AND LEVELS OF HEAVY METALS IN LETTUCE PLANTS FERTILIZED WITH ORGANIC COMPOUNDS

The use of organic compounds has been a good option to reduce spending on fertilizers, and gain increased productivity in the cultivation of lettuce. However, given the wide variety of raw materials used in the preparation of organic compounds, studies are needed to evaluate its effects on the release of essential nutrients to plants and on the release of contaminants such as heavy metals. The aim of this study was to evaluate the mineral nutrition and heavy metal contamination of lettuce in soils treated with doses and types of compost. The experiment was conducted in a greenhouse in randomized blocks in factorial scheme 5x4, with five types of organic compounds and four nitrogen levels (0, 35, 70 and 140 kg ha(-1) of N), with four replications. In general, the doses of the compounds were not enough to provide the necessary quantity of nutrients to the lettuce, with the exception of nitrogen. There was no increase in levels of heavy metals in the soil above that allowed by Brazilian legislation. Furthermore, compounds based on manure plus grass, and commercial compound caused increases in Zn concentration in plants at levels above the recommended for consumed.

Determinação de chumbo por análise voltamétrica de pulso diferencial por redissolução anódica em regiões de falhas geológicas com emissão de radônio e filhos de radônio no município de Presidente Prudente

Pós-graduação em Química - IBILCE

The effects of land use and soil management on the physical properties of an Oxisol in Southeast Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of cropping systems in no-till farming on the quality of a Brazilian Oxisol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cumulative long-term safety, efficacy and patient-reported outcomes in children with juvenile idiopathic arthritis treated with intravenous abatacept: up to 7 years of treatment

The long-term efficacy and safety of intravenous abatacept in patients (pts) with juvenile idiopathic arthritis (JIA) have been reported previously from the Phase III AWAKEN trial ([1, 2]). Here, we report efficacy, safety and pt-reported outcomes from the open-label, long-term extension (LTE) of AWAKEN, with up to 7 years of follow-up. Pts entered the LTE if they were JIA ACR 30 non-responders (NR) at the end of the 4-month lead-in period (abatacept only), or if they received abatacept or placebo (pbo) in the 6-month double-blind (DB) period. The Child Health Questionnaire was used to evaluate health-related quality of life (HRQoL); physical (PhS) and psychosocial (PsS) summary and pain scores were analyzed. Pain was assessed by parent global assessment using a 100 mm visual analog scale. Efficacy and HRQoL evaluations are reported up to Day 1765 (~ Year 5.5). Safety is presented for the cumulative period (lead-in, DB and LTE), for all pts who received abatacept during the LTE. Of the 153 pts entering the LTE (58 from DB abatacept group, 59 from DB pbo group, 36 NR), 69 completed the trial (29 abatacept, 27 pbo, 13 NR). For pts treated in the LTE, mean (range) exposure to abatacept was 53.6 (5.6–85.6) months. During the LTE, incidence rates of AEs and serious AEs per 100 pt-years were 209.1 and 5.6. Thirty pts (19.6%) had serious AEs; most were unrelated and were musculoskeletal (8.5%) or infectious events (6.5%). No malignancy was reported. There was one death (accidental; unrelated). At Day 169, JIA ACR 50 and 70 response rates were 79.3% and 55.2% in the abatacept group, and 52.5% and 30.5% in the pbo group; 31.0% and 10.2% of pts in the abatacept and pbo groups, respectively, had inactive disease. By Day 1765, JIA ACR 50 and 70 response rates were 93.9% and 78.8% in the abatacept group, and 80.0% and 63.3% in the pbo group; 51.5% and 33.3% had inactive disease. In the NR group, 69.2% and 53.8% of pts achieved JIA ACR 50 and 70 responses at Day 1765, and 30.8% had inactive disease. In pts who entered the LTE, mean baseline PhS scores were below the range for healthy children (abatacept 30.2, pbo 31.0, NR 29.5). At Day 169, 38.3% of pts had reached a PhS score >50 ((1). By the end of the LTE, 43.5% of pts had reached a PhS score >50. At baseline, mean PsS scores for those who entered the LTE were slightly lower than the mean for healthy children (abatacept 43.5, pbo 44.2, NR 47.0). At Day 169, 54.9% of pts had a PsS score >50 (1). By Day 1765, 58.1% of pts had reached a PsS score >50. At baseline, the mean pain score was 42.9. By Day 169, 13.9% of pts were considered pain free (pain score = 0); this was maintained over the LTE (1).

Influence of soil texture in the recovery of Toxocara canis eggs by a flotation method

In epidemiological surveys, the evaluation of soil contamination by Toxocara canis eggs requires a quick and easy method for the isolation of parasite eggs from soil samples. The efficiency of flotation methods is influenced by sample size, soil texture, degree of soil contamination, pretreatment, flotation solutions and time of flotation. This investigation was designed to evaluate the influence of soil texture in the recovery of T. canis eggs with the centrifugal flotation technique of Dada (Dada, B.J.O., 1979. A new technique for the recovery of Toxocara eggs from soil. J. Helminthol., 53: 141-144). Four types of soil (clay silt, sandy, silty clay and sand) were artificially contaminated with T. canis eggs (200 eggs per gram). Zinc sulphate (specific gravity 1.20) and sodium dichromate (specific gravity 1.35) were used as flotation solutions. Twenty replicated examinations were performed for each type of soil and flotation solution. There was a statistically significant difference in the results depending on soil type. The highest recovery percentages were observed in soils rich in sand (62.5% for sand and 38.0% for sandy soil). Differences were also observed with different flotation solutions. Sodium dichromate solution was more efficient for recovering T. canis eggs, regardless of the soil texture. © 1994.

Quantificação de metais potencialmente tóxicos em mexilhão dourado (Limnoperna fortunei) por espectrometria de absorção atômica com fonte contínua e alta resolução empregando amostragem direta de sólidos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

An Alternative Method for the Simultaneous Determination of Copper and Lead for Quality Control of Sugar Cane Spirit using a Nanotube-Based Sensor

The development of an electroanalytical method for simultaneous determination of copper and lead ions in sugar cane spirit (cachaca) using carbon paste electrode modified with ascorbic acid and carbon nanotubes (CPE-AaCNT) is described. Squarewave voltammetry (SWV) with anodic stripping was employed, and this technique was optimized with respect to the following parameters: frequency (50 Hz), amplitude (100 mV) and scan increment (9 mV). The analytical curves were linear in the range from 0.0900 to 7.00 mg L-1 for lead and copper. The limits of detection were 48.5 and 23.9 mu g L-1 for lead and copper, respectively. The developed method was applied to the simultaneous determination of copper and lead in five commercial samples of sugar cane spirit. The results were in good agreement with those obtained by F AAS/GF AAS (flame atomic absorption spectrometry/graphite furnace atomic absorption spectrometry) and showed that CPE-AaCNT can be successfully employed in the simultaneous determination of these metals in real sugar cane spirit samples.

Effects of catalyst load in Pt and Pb-based catalysts using formic acid oxidation as a model

In this paper, we discuss the effects of catalyst load with respect to carbon powder for several Pt and Pb-based catalysts, using formic acid as a model molecule. The discussion is based on electrochemical tests, a complete morphological investigation and theoretical calculations. We show that the Pt and Pb-based catalysts presented activity in formic acid oxidation at very low catalyst loads (e.g., 0.5% in respect to the carbon content). Physical characterisations demonstrate that the electrodes are composed of separated phases of Pt and lead distributed in Pt nanometric-sized islands that are heterogeneously dispersed on the carbon support and Pb ultra-small particles homogeneously distributed throughout the entire carbon surface, as demonstrated by the microscopy studies. At high catalyst loads, very large clusters of Pb(x)O(y) could be observed. Electrochemical tests indicated an increase in the apparent resistance of the system (by a factor of 19.7 Omega) when the catalyst load was increased. The effect of lead in the materials was also studied by theoretical calculations (OFT). The main conclusion is that the presence of Pb atoms in the catalyst can improve the adsorption of formic acid in the catalytic system compared with a pure Pt-based catalyst. (C) 2011 Elsevier B.V. All rights reserved.

A 2400-year record of trace metal loading in lake sediments of Lagoa Vermelha, southeastern Brazil

Sediments of the Lagoa Vermelha (Red Lake), situated in the Ribeira Valley, southeastern Brazil, are made of a homogeneous, organic-rich, black clay with no visible sedimentary structures. The inorganic geochemical record (Al, As, Ba, Br, Co,Cs, Cr, Fe, Mn, Ni, Rb, Sc, Sb, V, Zn, Hg and Pb) of the lake sediments was analyzed in a core spanning 2430 years. The largest temporal changes in trace metal contents occurred approximately within the last 180 years. Recent sediments were found to be enriched in Pb, Zn, Hg, Ni, Mn, Br and Sb (more than 2-fold increase with respect to the "natural background level"). The enhanced accumulation of Br, Sb, and Mn was attributed to biogeochemical processes and diagenesis. On the other hand, the anomalous concentrations of Pb, Zn, Hg and Ni were attributed to pollution. As Lagoa Vermelha is located in a relatively pristine area, far removed from direct contamination sources, the increased metal contents of surface sediments most likely resulted from atmospheric fallout. Stable Pb isotopes provided additional evidence for anthropogenic contamination. The shift of Pb-206/Pb-207 ratios toward decreasing values in the increasingly younger sediments is consistent with an increasing contribution of airborne anthropogenic lead. In the uppermost sediments (0-10 cm), the lowest values of the Pb-206/Pb-207 ratios may reflect the influence of the less radiogenic Pb from the Ribeira Valley District ores (Pb-206/Pb-207 between 1.04 and 1.10), emitted during the last 50 years. (C) 2011 Elsevier Ltd. All rights reserved.

Phosphorus Availability in an Oxisol Amended with Biosolids in a Long-Term Field Experiment

Many extractors are used to quantify available P in soils, but few studies have assessed the availability of P in soils of the wet tropics amended with high rates of biosolids. In this study, ion exchange resin, Mehlich-1 solution, and Fe-impregnated strips were used to quantify available P in samples from an Oxisol amended with surface-applied biosolids in a long-term field experiment. The soil's maximum capacity for P adsorption was also estimated. Experimental design consisted of randomized blocks, with four treatments and three replicates. Samples of biosolids were collected every year during the experiment, from 1999 to 2002. In 1999, two applications were made before growing maize (Zea mays L.) in austral summer and winter. Treatments were: Control (no biosolids added); B (biosolids added at rates based on their total N content); B2 (biosolids added at twice the rate of B), and B4 (biosolids added at four times the rate of B). Soil samples were collected at 0- to 0.1-, 0.1- to 0.2-, and 0.2- to 0.4-m depths. Biosolids were broadcast applied and incorporated into the soil to a depth of 0.2 m using a rotary hoe. The Oxisol had a high P-adsorption capacity (around 2450 mg kg(-1)) because of its high contents of clay and Fe and Al oxides. All the extractors were effective at assessing P availability and were positively correlated among themselves. Available P soil contents correlated positively with P content in maize leaves and grains, and the resin method yielded the highest correlation with P contents in leaves and grains.

Fluoride plus CO2 laser against the progression of caries in root dentin

Purpose: To evaluate the effect of a 1.23% acidulated phosphate fluoride (APF) gel combined with CO2 laser in protecting carious root dentin against further cariogenic challenges. Methods: After a 7-day lead-in period, 12 volunteers wore an intraoral palatal device containing four carious root dentin slabs, treated with APF and APF+CO2 or placebo and placebo+CO2. After a 14-day wash-out period, volunteers were crossed-over to the other treatment arm. During both intraoral phases, specimens were submitted to cariogenic challenges and then evaluated for cross-sectional Knoop microhardness. Results: Two-way ANOVA demonstrated that there was significant effect for both main factors: CO2 laser irradiation (P< 0.0001) and gel treatment (P< 0.0001), and that there was no interaction between them (P= 0.4706). Protection of carious root dentin against further cariogenic challenges may be provided by APF fluoride gel and CO2 laser, but no additive benefit was found by combining such strategies. (Am J Dent 2012;25:114-117).

In Situ Effect of Dentifrices Associated to CO2 Laser in the Permeability of Eroded Root Dentin

Objective: The aim of this study was to evaluate, through a crossover 2 x 2 in situ trial, the effect of a desensitizing dentifrice associated with CO2 laser irradiation to control the permeability of eroded root dentin. Background data: Facing the increased prevalence of erosive lesion and the need for preventive means to control painful symptoms related to them. Methods: Eighty slabs of bovine root dentin were subjected to initial erosive challenge (citric acid 0.3%, 2 h), followed by a remineralizing period in artificial saliva (24 h). Specimens were then divided according to dentin treatment: desensitizing dentifrice, desensitizing dentifrice + CO2 laser, fluoride anticavity dentifrice. and fluoride anticavity dentifrice + CO2 laser. After a 2-day lead-in period, 10 volunteers wore an intraoral palatal appliance containing four root dentin slabs, in two phases of 5 days each. During the intraoral phase, one side of the appliance was immersed in 0.3% citric acid, and the opposite side was immersed in deionized water, four times a day. One hour after the immersions, all specimens were brushed with dentifrice slurry provided by the researcher. After a 7-day washout period, volunteers were crossed over on the different dentifrice group. Each phase having been completed, the specimens were evaluated for permeability through an optical microscope. Results: Data were analyzed using ANOVA and no significant difference (p = 0.272) was found between the surface treatments performed on bovine root dentin. Conclusions: It can be concluded that fluoride anticavity or desensitizing dentifrice, regardless of the association with the CO2 laser irradiation, was able to control the permeability of eroded root dentin.

Integrated ecological risk assessment of pesticides in tropical ecosystems: A case study with carbofuran in Brazil

The aim of the present study is to contribute an ecologically relevant assessment of the ecotoxicological effects of pesticide applications in agricultural areas in the tropics, using an integrated approach with information gathered from soil and aquatic compartments. Carbofuran, an insecticide/nematicide used widely on sugarcane crops, was selected as a model substance. To evaluate the toxic effects of pesticide spraying for soil biota, as well as the potential indirect effects on aquatic biota resulting from surface runoff and/or leaching, field and laboratory (using a cost-effective simulator of pesticide applications) trials were performed. Standard ecotoxicological tests were performed with soil (Eisenia andrei, Folsomia candida, and Enchytraeus crypticus) and aquatic (Ceriodaphnia silvestrii) organisms, using serial dilutions of soil, eluate, leachate, and runoff samples. Among soil organisms, sensitivity was found to be E. crypticus < E. andrei < F. candida. Among the aqueous extracts, mortality of C. silvestrii was extreme in runoff samples, whereas eluates were by far the least toxic samples. A generally higher toxicity was found in the bioassays performed with samples from the field trial, indicating the need for improvements in the laboratory simulator. However, the tool developed proved to be valuable in evaluating the toxic effects of pesticide spraying in soils and the potential risks for aquatic compartments. Environ. Toxicol. Chem. 2012;31:437-445. (C) 2011 SETAC

Sequential extraction of phosphorus in an Oxisol amended with biosolids in a long-term field experiment in Brazil

The continued growth of large cities is producing increasing volumes of urban sewage sludge. Disposing of this waste without damaging the environment requires careful management. The application of large quantities of biosolids (treated sewage sludge) to agricultural lands for many years may result in the excessive accumulation of nutrients like phosphorus (P) and thereby raise risks of eutrophication in nearby water bodies. We evaluated the fractionation of P in samples of an Oxisol collected as part of a field experiment in which biosolids were added at three rates to a maize (Zea mays L) plantation over four consecutive years. The biosolids treatments were equivalent to one, two and four times the recommended N rate for maize crops. In a fourth treatment, mineral fertilizer was applied at the rate recommended for maize. Inorganic P forms were extracted with ammonium chloride to remove soluble and loosely bound P; P bound to aluminum oxide (P-Al) was extracted with ammonium fluoride; P bound to iron oxide (P-Fe) was extracted with sodium hydroxide; and P bound to calcium (P-Ca) was extracted with sulfuric acid. Organic P was calculated as the difference between total P and inorganic P. The predominant fraction of P was P-Fe, followed by P-Al and P-Ca. P fractions were positively correlated to the amounts of P applied, except for P-Ca. The low values of P-Ca were due to the advanced weathering processes to which the Oxisol have been subjected, under which forms of P-Ca are converted to P-Fe and P-Al. The fertilization with P via biosolids increased P availability for maize plants even when a large portion of P was converted to more stable forms. Phosphorus content in maize leaves and grains was positively correlated with P fractions in soils. From these results it can be concluded that the application of biosolids in highly weathered tropical clayey soils for many years, even above the recommended rate based on N requirements for maize, tend to be less potentially hazardous to the environment than in less weathered sandy soils because the non-readily P fractions are predominant after the addition of biosolids. (C) 2012 Elsevier B.V. All rights reserved.