Silvana do Couto Jacob

Avaliação integrada do impacto do uso de agrotóxicos sobre a saúde humana em uma comunidade agrícola de Nova Friburgo, RJ

O impacto do uso de agrotoxicos sobre a saude humana e um problema que tem merecido atencao da comunidade cientifica em todo o mundo, sobretudo nos paises em desenvolvimento. O consumo de agrotoxicos na regiao sudeste do Brasil esta estimado em 12kg de agrotoxico/trabalhador/ano. Em algumas areas agricolas do Estado do Rio de Janeiro, como na regiao da Microbacia do Corrego de Sao Lourenco, Nova Friburgo, o consumo de agrotoxico foi estimado em 56kg de agrotoxico/trabalhador/ano. Elevados niveis de contaminacao humana e ambiental foram encontrados nesta regiao, como decorrencia do uso extensivo destes agentes quimicos. A avaliacao do impacto sobre a saude humana implica o conhecimento e a visualizacao da importância/magnitude relativa de cada uma das vias de contaminacao. Inumeros fatores, que, em geral, encontram-se inter-relacionados, contribuem para a situacao encontrada na Microbacia do Corrego de Sao Lourenco e a forma mais adequada de se avaliar toda a dimensao deste problema e o uso de uma abordagem integrada.

Dietary intake and health effects of selected toxic elements

Anthropogenic activities have being contributing to the spread of toxic chemicals into the environment, including several toxic metals and metalloids, increasing the levels of human exposure to many of them. Contaminated food is an important route of human exposure and may represent a serious threat to human health. This mini review covers the health effects caused by toxic metals, especially Cd, Hg, Pb and As, the most relevant toxic elements from a human health point of view.

Exposição múltipla a agrotóxicos e efeitos à saúde: estudo transversal em amostra de 102 trabalhadores rurais, Nova Friburgo, RJ

Um estudo transversal foi realizado em uma comunidade agricola localizada em Nova Friburgo, RJ, para conhecer os aspectos epidemiologicos, clinicos e laboratoriais da exposicao multipla a agrotoxicos em uma amostra representativa de 102 pequenos agricultores, de ambos os sexos. Os trabalhadores foram submetidos a um extenso protocolo que incluia aplicacao de questionario ocupacional, coleta de amostras biologicas para exame toxicologico e avaliacao clinica - geral e neurologica. Os resultados dos exames toxicologicos revelaram episodios leves a moderados de intoxicacao aguda aos organofosforados descritos pelos agricultores ou observados durante o exame clinico. Foram tambem diagnosticados 13 (12,8 %) quadros de neuropatia tardia e 29 (28,5%) quadros de sindrome neurocomportamental e disturbios neuropsiquiatricos associados ao uso cronico de agrotoxicos. Os resultados apontam para a ocorrencia de episodios recorrentes de sobre-exposicao multipla, a elevadas concentracoes de diversos produtos quimicos, com grave prejuizo para as funcoes vitais desses trabalhadores, especialmente por se encontrarem em uma faixa etaria jovem (media = 35 ± 11anos) e periodo produtivo da vida. Estes dados demonstram a importância do monitoramento da multipla exposicao a agrotoxicos, uma cadeia de eventos de grande repercussao na saude publica e para o meio ambiente.

Simultaneous determination of Cd and Fe in grain products using direct solid sampling and high-resolution continuum source electrothermal atomic absorption spectrometry.

Cadmium and iron are antagonistic elements in the sense that they produce different effects in the human body. Both elements have to be determined routinely in grain products, cadmium because of its toxicity, and iron because all grain products, according to Brazilian law, have to contain a minimum of 42 mg kg(-1) Fe to combat anemia. A routine screening method has been developed for the quasi simultaneous determination of cadmium and iron using high-resolution continuum source electrothermal atomic absorption spectrometry and direct solid sampling. The primary absorption line at 228.802 nm has been used for Cd, and an adjacent secondary line at 228.726 nm for the determination of Fe. Various chemical modifiers have been investigated, and a mixture of tungsten and iridium, applied as a permanent modifier, showed the best performance; it stabilized Cd up to a pyrolysis temperature of 700 degrees C and did not over-stabilize Fe. Two atomization temperatures were used sequentially, 1700 degrees C for Cd and 2600 degrees C for Fe, because of their significantly different volatilities. The characteristic masses obtained were 0.9 pg for Cd and 1.2 ng for Fe. The limits of detection (3 sigma, n=10) were 0.6 microg kg(-1) for Cd and 0.5 mg kg(-1) for Fe. The relative standard deviation ranged from 3 to 7% for Cd and from 4 to 13% for Fe, which is satisfactory for the purpose. The accuracy of the method was confirmed by the analysis of three certified reference materials; the results were in agreement with the certified values at a 95% confidence interval. The Cd content in the investigated grain products was between 0.9 and 10.5 microg kg(-1), but most of them did not contain the required minimum amount of iron.

Simultaneous determination of Cd and Fe in beans and soil of different regions of Brazil using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling.

A fast routine screening method for the simultaneous determination of cadmium and iron in bean and soil samples is proposed, using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling. The primary absorption line at 228.802 nm has been used for the determination of cadmium, and an adjacent secondary line, at 228.726 nm, for iron. Fourteen bean samples and 10 soil samples from nine states all over Brazil have been analyzed. The limits of detection (3 sigma, n = 10) were 2.0 microg kg(-1) for Cd and 4.5 mg kg(-1) for Fe. The relative standard deviation ranged from 4 to 7% for Cd and from 5 to 28% for Fe, which is usually acceptable for a screening method. The accuracy of the method has been confirmed by the analysis of two certified reference materials; the results were in agreement with the certified values at a 95% confidence interval.

A propaganda de alimentos: orientação, ou apenas estímulo ao consumo?

Current advertising messages for food products deserve special attention, since they indicate that the media has played a central role in shaping new eating habits. The food industry, seeking to serve a new customer segment (increasingly preoccupied with health and physical well-being), and with a specific interest in this promising market, has intensified its marketing strategies for stimulating consumption of diet and light food products. This study analyzed 20 food advertisements published from June to October 2006 in Brazilian magazines and newspapers with nationwide circulation. The following elements were analyzed in the advertisements: the advertiser; the audience; the language; and the message. It was seen that the advertising message mainly targeted women, proposing guilt-free consumption, promising a combination of esthetics and health. In order to enhance their product, several advertisements omitted relevant nutritional information while others promoted hazardous combinations with pharmaceutical products, and still others induced the target public to replace regular meals with their product. The results signal the need to broaden the discussion on the strategies for food advertising, as the citizens right to information and health cannot be subjugated to market values.

Avaliação qualitativa do hábito de leitura e entendimento: recepção das informações de produtos alimentícios

A rotulagem de alimentos e o principal elo entre o consumidor e o produto, alem de representar um importante instrumento de educacao alimentar. O presente estudo avaliou o habito de leitura e compreensao dos rotulos de produtos alimenticios pelos frequentadores de supermercados do municipio de Niteroi/RJ - nos meses de setembro a dezembro de 2003. Foram realizadas entrevistas individuais (estudo quali-quantitativo) nas quais foi usado como instrumento de estudo um questionario sobre os rotulos, que foi aplicado a 400 individuos. Os resultados referentes a parte qualitativa do estudo evidenciaram que os principais problemas na compreensao da rotulagem dos produtos alimenticios foram: a baixa confianca pelos consumidores nas informacoes vinculadas pelos rotulos; o uso da linguagem tecnica; o excesso de propagandas veiculadas pelas diversas midias; e a pouca informacao sobre componentes alimentares potencialmente alergenicos. O estudo apontou a necessidade do desenvolvimento de politicas publicas de comunicacao para melhor orientar os consumidores na escolha de seus alimentos atraves da rotulagem de alimentos, estimulando-os no desenvolvimento de praticas alimentares mais adequadas.

Comparative study of transgenic and non-transgenic maize (Zea mays) flours commercialized in Brazil, focussing on proteomic analyses

Genetically modified foods are a major concern around the world due to the lack of information concerning their safety and health effects. This work evaluates differences, at the proteomic level, between two types of crop samples: transgenic (MON810 event with the Cry1Ab gene, which confers resistance to insects) and non-transgenic maize flour commercialized in Brazil. The 2-D DIGE technique revealed 99 differentially expressed spots, which were collected in 2-D PAGE gels and identified via mass spectrometry (nESI-QTOF MS/MS). The abundance of protein differences between the transgenic and non-transgenic samples could arise from genetic modification or as a result of an environmental influence pertaining to the commercial sample. The major functional category of proteins identified was related to disease/defense and, although differences were observed between samples, no toxins or allergenic proteins were found.

Validation of a liquid chromatography–electrospray ionization tandem mass spectrometric method to determine six polyether ionophores in raw, UHT, pasteurized and powdered milk

This study aimed to validate a method developed for the determination of six antibiotics from the polyether ionophore class (lasalocid, maduramicin, monensin, narasin, salinomycin and semduramicin) at residue levels in raw, UHT, pasteurized and powdered milk using QuEChERS extraction and high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The validation was conducted under an in-house laboratory protocol that is primarily based on 2002/657/EC Decision, but takes in account the variability of matrix sources. Overall recoveries between 93% and 113% with relative standard deviations up to 16% were obtained under intermediate precision conditions. CCα calculated values did not exceed 20% the Maximum Residue Limit for monensin and 25% the Maximum Levels for all other substances. The method showed to be simple, fast and suitable for verifying the compliance of raw and processed milk samples regarding the limits recommended by Codex Alimentarius and those adopted in European Community for polyether ionophores.

Comparison of the nutritional and toxicological reference values of trace elements in edible marine fish species consumed by the population in Rio De Janeiro State, Brazil

The present study estimated the human daily and weekly intake of inorganic elements due to consumption of fish in Rio de Janeiro state and the associated potential health risks posed by some toxic elements. All samples analyzed had values of Cd and Pb below the Maximum Tolerable Limits of 3.0 mg kg−1 for Pb and 1.0 mg kg−1 for Cd; only Mugil cephalus, Cynoscion leiarchus and Caranx crysos had As concentrations below 1 mg kg−1, maximum limit established by Brazilian legislation. The higher values of Cd and Pb correspond to 0.22% of PTWI and the higher value of As corresponds to 8.6% of PTWI. None of the studied species showed values higher than PTWI. The higher values of Cu EDI found in Pomatomus numida correspond to 33.3% of RDA; Fe in Salmo salar and Genypterus brasiliensis corresponds to 4.3% of EDI; Mn in Sardinella brasiliensis corresponds to 7.4% of EDI; Zn in S. salar corresponds to 13.2% of EDI and Se in S. salar corresponds to 20.6% of EDI. Some species can be a good source of inorganic elements. For risk assessment, it is important to assess specific eating habits of each region to avoid underestimating the data.