Anderson Ricardo Trevizam

Heavy metals in vegetables and potential risk for human health

Ingestion of vegetables containing heavy metals is one of the main ways in which these elements enter the human body. Once entered, heavy metals are deposited in bone and fat tissues, overlapping noble minerals. Slowly released into the body, heavy metals can cause an array of diseases. This study aimed to investigate the concentrations of cadmium, nickel, lead, cobalt and chromium in the most frequently consumed foodstuff in the Sao Paulo State, Brazil and to compare the heavy metal contents with the permissible limits established by the Brazilian legislation. A value of intake of heavy metals in human diets was also calculated to estimate the risk to human health. Vegetable samples were collected at the Sao Paulo General Warehousing and Centers Company, and the heavy metal content was determined by atomic absorption spectrophotometry. All sampled vegetables presented average concentrations of Cd and Ni lower than the permissible limits established by the Brazilian legislation. Pb and Cr exceeded the limits in 44 % of the analyzed samples. The Brazilian legislation does not establish a permissible limit for Co contents. Regarding the consumption habit of the population in the Sao Paulo State, the daily ingestion of heavy metals was below the oral dose of reference, therefore, consumption of these vegetables can be considered safe and without risk to human health.

Concentração de metais pesados em grãos de plantas cultivadas em solo com diferentes níveis de contaminação

The aim of this work was to evaluate the absorption and capacity of translocation of heavy metals from the soil to rice and soybean grains. Experiment was carried out in a greenhouse using a dystrophic Typic Hapludox soil from the district of Paulinia, SP. Soil samples were collected in seven different points and were organized according to the distance from a factory, source of pollution. The experimental design used was the completely randomized, with four replications. The roots, aerial leaves and grains were submitted to humid digestion. The concentrations of heavy metals were determined by ICP-OES. Cadmium and copper concentrations in the grains were at normal levels for both cultures, however manganese and zinc concentrations were in excess, according to the levels of soil contamination, possibly being able to reach top trophic levels. The roots limited the translocation of cadmium, copper, iron and lead to the aerial parts of both cultures. Although the translocation of lead was also limited by the roots, it was present in high concentrations in soy grains and, well as manganese and zinc, it can reach the food chain.

Improving phosphorus availability from patos phosphate rock for Eucalyptus: a study with 32P radiotracer

Como geralmente os solos usados para plantacoes de eucalipto no Brasil sao de baixa fertilidade, a adubacao fosforica e indispensavel, incrementando o custo da plantacao. Especies mais eficientes no uso de fosforo (P) de fontes pouco soluveis poderiam ser uma opcao interessante. Porem, pouco se conhece ainda sobre o comportamento de eucalipto em relacao a capacidade de usar fosforo de fontes com diferente solubilidade em agua. O uso de P por eucalipto (E. urophylla, E. grandis, and E. urophylla ´ E. grandis), foi estudado em experimento de casa de vegetacao usando solo da Regiao de Cerrado, Latossolo Vermelho Amarelo hypodistrofico, e o metodo isotopico com 32P. As fontes de P usadas foram superfosfato triplo (SFT), rocha fosforica (RF) e a mistura de superfosfato triplo com rocha fosforica (SFT+RF). A eficacia das fontes de P em termos do aumento do rendimento de materia seca seguiu a ordem SFT = (SFT + RF) > RF e de P absorvido a ordem (SFT + RF) > SFT > RF por ambas as especies e o hibrido de eucalipto. O incremento na absorcao de P de RF, influenciada pela mistura com SFT foi de 217,3% em E. urophylla, 235,7% em E. grandis e 28,7% em E. urophylla ´ E. grandis, indicando o efeito benefico do SFT sobre a efetividade da RF. O hibrido E. urophylla ´ E. grandis foi o genotipo mais eficiente no uso de P do solo e E. grandis o mais exigente em P do fertilizante.

Heavy metal toxicity in rice and soybean plants cultivated in contaminated soil

Os metais pesados podem-se acumular no solo, causando fitotoxicidade em plantas, apresentando alguns sintomas especificos. Por esta razao, este estudo avaliou os sintomas especificos, em plantas de arroz e de soja, causados por excesso de metais pesados no solo. As plantas de arroz e de soja foram cultivadas em vasos, contendo solos com diferentes quantidades de metais pesados. O delineamento experimental foi inteiramente casualizado, com quatro repeticoes, utilizando-se duas culturas e sete amostras de solos com diferentes niveis de contaminacao. As plantas de arroz e de soja exibiram diferentes respostas as elevadas concentracoes desses metais no solo. Por exemplo, altas concentracoes de Zn disponivel no solo causaram fitotoxicidade no arroz e na soja, principalmente cloroses e inibicao do crescimento das plantas. As plantas de arroz acumularam maiores teores de Cu, Mn, Pb e Zn e foram mais sensiveis as concentracoes elevadas desses elementos no solo, absorvendo-os mais facilmente do que as plantas de soja. Alem disso, altas concentracoes de Zn no solo reduziram a concentracao de Fe na parte aerea das plantas de soja e de arroz para niveis considerados deficientes.

Aplicação de fósforo para imobilização química do cádmio em solo contaminado

The objective of the study was to evaluate the effect of phosphorus on the Cd availability to plants of a contaminated soil using 109Cd isotope and chemical extractants. The experiment was set in a randomized block design and the soil was labeled with 222 KBq of 109Cd per pot and received 5 rates of P as triple superphosphate, growing lettuce plants as test crop. The use of phosphorus reduced pH of soil which altered the Cd availability in DTPA and Mehlich extractants. The lettuce Cd content decreased but its accumulation and L value increased in all treatments compared to the control, demonstrating the inefficiency of phosphorus in reducing the Cd availability.

Fitodisponibilidad de Cd en suelo de diferente pH tratado con lodo albañal estimada por método isotópico y extracción química

The Cd phytoavailability in sewage sludge-amended soils of different pHs using the 109Cd L-value isotopic method and Cd extracted by DTPA has been determined. Maize plants (Zea mais L.) were grown under greenhouse conditions in a xanthic ferralsol at different pHs amended with five sewage sludge (SS) rates, and labeled with 74 kBq kg-1 of 109Cd. The SS rates altered the properties of the soil chemicals and these influenced the isotopic parameter (L-value) and percent of Cd uptake by plants from soil (%Cdpdfs) and SS (%CdpdfSS). L-values and Cd extracted by DTPA correlate significantly with SS rates and Cd uptake by plants and are efficient for predicting the Cd phytoavailability in the sewage sludge-amended soil.

Copper and zinc quantification in contaminated soil as evaluated by chemical extractants

Trace elements are potentially toxic to the environment. Their toxicity in soils relies on their type of chemical associations. Hence it is important to determine the chemical form they occur in the soils in order to assess their quantities. The objective the present work was to evaluate the possibility of using the concentrations of Cu and Zn in different soil fractions and the total concentration as predictors of their quantification by comparing the classical extractants DTPA, Mehlich-1 and HCl. Comparisons were made also with the concentrations of absorbed by rice and soybean in contaminated soil. Seven soil samples with a different degree of contamination were studied using a randomized experimental design, with four replicates. By using an ICP-OES we analyzed the concentrations of Cu and Zn in the diagnostic leafs, at the end of the cycle (LCE) and several of its content in the soil: available extracted with the DTPA, Mehlich-1 and HCl extractants, soluble+exchangeable contents, bound to organic matter, to oxides and the total content. For both, soybean and rice, the concentrations of Cu and Zn extracted from the sequential extraction was found to be correlated with the concentration in LCE. For soybean, Zn concentration extracted with DTPA was correlated with the total concentration, while Cu concentration extracted with three extractors, DTPA, Mehlich-1 and HCl, correlated with the total concentration, probably due to the high concentration of Cu and Zn in this soil. For rice, both Cu and Zn concentration as extracted by the three extracting solutions correlated with the concentration of all the fractions and with the total concentration.

Alteraciones químicas y fitodisponibilidad de níquel en suelo tratado con lodo albañal

The alteration of soil chemicals and its influence on availability (DTPA extractant method) and phytoavailability (63Ni L-value, isotopic method) of Ni was studied in sewage sludge-amended soil at different pHs. The soil pHs were 4.3, 5.3 and 5.9 and the rates of sewage sludge (SS) 0, 15, 30, 45 and 60 Mg ha-1. The chemical and physicochemical soil characteristics were altered by the SS rate and increased the Ni availability and phytoavailability. The isotopic method (63Ni L-value) was more efficient in predicting the Ni phytoavailability that the Ni-DTPA extractant in soil pHs 5.3 and 5.9.

Influência do nitrogênio e enxofre na produção do feijoeiro

Na fisiologia das plantas, limitacoes de nitrogenio (N) ou enxofre (S) sao manifestadas no ponto de convergencia das rotas assimilatorias, o que ocasiona acumulo ou carencia de produtos sintetizados. O objetivo do trabalho foi avaliar a influencia da interacao entre o N e S no desenvovlimento da cultura do feijoeiro. O experimento foi conduzido em casa de vegetacao, em vasos contendo 4 dm 3 de solo. O experimento foi instalado em esquema fatorial 2 x 5, sendo duas doses de N (80 e 120 mg dm -3 ) e cinco doses de S (0, 30, 60, 90 e 120 mg dm -3 ), com tres repeticoes por tratamento. Os tratamentos foram aplicados aos vasos e semeado o feijao. O experimento foi conduzido por 80 dias, ao final do ciclo as plantas foram separadas em graos e parte aerea. As amostras vegetais da parte aerea foram secas, moidas e analisadas em relacao ao teor de N e S. A produtividade de graos do feijoeiro foi influenciada pela adubacao nitrogenada e sulfatada, sendo que o mesmo nao ocorreu para a producao de materia seca da parte aerea. A absorcao de S pela cultura do feijoeiro foi diretamente influenciada pela adubacao nitrogenada. A relacao N/S na cultura do feijoeiro foi diretamente influenciada pela adicao de N e S. Os valores de N/S nao correlacionaram-se com a producao de graos ou materia seca da parte aerea.

Gesso agricola como fonte de enxofre para a cultura do morango

There are several studies on plant responses to Sulfur (S), but few are specific to the strawberry crop. The requirement for nutrients and the nutritional status of plants is a particular attribute of each species that should be taken into account when determining the plant’s nutritional demand. The objective of this study was to evaluate the application of S and phosphate (P) rates in the development and productivity of strawberry crops. An experiment was conducted in a greenhouse in pots containing 2 kg soil (Oxisol) in Guarapuava city of Paraná State. The experiment consisted of a 6 × 2 factorial outlined in a randomized block design with three replications, with six doses of S: 0, 10, 20, 30, 40 and 50 mg kg-1 in the form of gypsum, and two doses of P: 300 and 600 mg kg-1 of P2O5. The Albion variety of strawberry plants was transplanted to pots and grown for 170 days. The fruits were harvested and weighed throughout the experiment; a similar procedure was followed for the shoots at the end of the experiment. The shoots and fruits were dried, weighed, ground, and analyzed for the content of S, Ca, and P. The production of strawberry fruits was influenced by S rates, with the highest productivity obtained by using S rates of 60 and 37 mg kg-1 with the application of 300 and 600 mg kg-1 of P, respectively.