DISSIPAÇÃO DE ENDOSSULFAN EM AMOSTRAS DE DOIS TIPOS DE SOLOS BRASILEIROS TRATADAS EM LABORATÓRIO

Avaliou-se a persistência e a degradação de Endossulfan em gleissolo húmico (GH) e argissolo vermelho-amarelo (AA), com diferentes características químicas e físicas, tratados em laboratório com solução de 14C-endossulfan. Determinou-se a persistência a partir da produção de 14CO2 aos 7, 14, 21 e 28 dias após o tratamento. A degradação foi avaliada aos 0, 30, 60 e 90 dias após o tratamento pela extração das amostras, análise dos extratos e combustão das amostras extraídas. O radiocarbono presente (extraível e ligado) foi quantificado por espectrometria de cintilação em líquido. Alíquotas dos extratos foram analisadas por cromatografia em camada delgada (CCD) quanto à presença de produtos de degradação. Nos dois tipos de solo, a persistência ambiental e o padrão de degradação mostraram-e semelhantes. Os valores detectados para a produção de 14CO2, em ambos os tipos de solo, evidenciaram meia-vida entre 90 e 180 dias. Ocorreu diminuição na recuperação de 14C-resíduos extraíveis e aumento de 14C-resíduos ligados aos 0, 30, 60 e 90 dias, sendo a porcentagem desses últimos maior no solo GH (cerca de 8 %) do que no solo AA (cerca de 6%). A CCD revelou nos dois tipos de solos a presença dos produtos de degradação endossulfan-diol, logo após o tratamento, endossulfan-sulfato e outro nãoidentificado aos 30, 60 e 90 dias, provavelmente relacionados com a sua biodegradação. ENDOSULFAN DISSIPATION IN TWO BRAZILIAN SOIL SAMPLES TREATED IN LABORATORY Abstract Persistant and degradation of Endosulfan in different soils (GH and AA) with distinct chemical and physical characteristics were evaluated by treatment with 14C-endosulfan solution. Persistance was determined from the production of 14CO2, 7, 14, 21 and 28 days after treatment. Degradation was evaluated at 0, 30, 60 and 90 days after treatment by sample extraction, extract analysis and combustion of extracted samples. The radiocarbon (extractable and bound) was quantified by cintilation spectroscopy. Aliquots of the extracts were analysed by thyn layer chromatography (TLC) for the presence of degradation products. In both soil samples, environmental persistance and degradation standard were similar. The values detected for the production of 14CO2 in both soils evidenced half-life between 90 and 180 days. Reduction in the recuperation of 14C- extractable residues occured and augmented for bound 14C residues at 0, 30, 60 and 90 days, being the latter percentage higher in GH soil (around 8%) than in AA soil (around 6%). TLC showed in both soils the presence of endosulfan-diol degradation products right after the treatment, endosulfan-sulphate and other non identified at 30, 60 and 90 days, probably related with its biodegradation

Persistence of chlorpyrifos in greenhouse air Persistência do inseticida clorpirifós no ar em casa de vegetação

RESUMO: Os inseticidas organofosforados estão entre os agrotóxicos de maior toxicidade aguda disponíveis no mercado e são usados em várias regiões do Brasil. Avaliaram-se a concentração e o tempo de permanência do inseticida organofosforado clorpirifós no ar, após aplicação em uma casa de vegetação. O clorpirifós permaneceu no ar da casa de vegetação em concentração três vezes acima do limite de exposição ocupacional por mais de 24 horas, e ainda foi detectado após quatro dias. PALAVRAS-CHAVE: inseticidas organofosforados, exposição ocupacional, período de reentrada. ABSTRACT: Organophosphate pesticides are among those with the highest acute toxicity and are available on the market and used in several regions of Brazil. The concentration and residence time of the organophosphate pesticide, chlorpyrifos, in the air after application in a greenhouse were investigated. For more than 24 h, the chlorpyrifos remained in the greenhouse air at concentrations three times above the occupational exposure limit and was still detectable four days later

Current status of rodenticide intoxication in Brazil: a preliminary survey from 2009 to 2011

The chemical control of rodents with anticoagulant products, especially derivatives of the coumarin chemical group, is legally authorised in Brazil. These products provide effective control and are safe for humans. However, the use of illegal 'rodenticides' has increased in many Brazilian cities recently, accompanied by increased numbers of suicides, homicides, and intoxications. The National Toxicology Information System (Sinitox) registers the number of rodenticide intoxications, including suicides, but does not differentiate between the legal and illegal rodenticides. Intoxications by rodenticides outnumber those by illicit drugs and pesticides. A survey of data from 2005-2011 revealed an average of about 3,800 intoxications per year, about 60% of which were suicides. Many of these intoxications probably involved illegal rodenticides, some with unknown chemical compositions, which confound the data on rodenticide intoxication. This evaluation of Sinitox data highlighted the need to ensure the proper use of the term 'rodenticide' when registering intoxication cases. Intoxication by-products that are not rodenticides, but are erroneously used for this purpose, should be classified separately to improve the quality of information

Enhanced degradation of metalaxyl in agricultural soils of São Paulo State, Brazil

This work investigated the effect of repeated applications on enhanced degradation of metalaxyl in two different agricultural soils used for cultivation of orange and lemon from Casa Branca and Itapetininga districts of São Paulo State, Brazil. Soil samples were collected from areas repeatedly treated with commercial ridomil 50GR for six successive years, and from other areas never exposed to this fungicide. At the laboratory, soil samples received a 14C-metalaxyl solution and its degradation was studied through radiometric techniques to measure biomineralization and recovery of extractable- and soil-bound products. Enhanced degradation was verified only in one soil, although partial degradation and mineralization of the fungicide were detected in both soils. The different rates and patterns of metalaxyl degradation in the soils were probably due to their different physical, chemical, and biological characteristics

Avaliação da vestimenta utilizada como equipamento de proteção individual pelos aplicadores de malationa no controle da dengue em São Paulo, Brasil

O inseticida malationa em calda oleosa é utilizado no controle do Aedes aegypti e a sua aplicação é feita por meio de nebulização. Essa atividade exige o uso de equipamento de proteção individual (EPI) pelos aplicadores. Este trabalho avaliou a capacidade de retenção do inseticida malationa nas vestimentas do EPI após nebulização em campo. Foram acompanhadas nebulizações em campo, realizadas pelos agentes de zoonoses, na cidade de São Paulo, Brasil. Antes de cada nebulização eram colocados absorventes sob e sobre a vestimenta do EPI no tórax, na face superior da parede torácica (costas) e nos antebraços. Após cada aplicação, os absorventes eram retirados, identificados e submetidos à extração sob agitação mecânica. Os extratos foram analisados por cromatografia a gás com detector de ionização de chama. Observou-se a presença de malationa nos absorventes sob as vestimentas do EPI já na primeira aplicação, antes da lavagem. Os resultados indicam que os agentes, nas condições avaliadas, estão expostos ao malationa, mesmo com uso de vestimentas de EPI novos

Persistence of chlorpyrifos in greenhouse air

ABSTRACT: Organophosphate pesticides are among those with the highest acute toxicity and are available on the market and used in several regions of Brazil. The concentration and residence time of the organophosphate pesticide, chlorpyrifos, in the air after application in a greenhouse were investigated. For more than 24 h, the chlorpyrifos remained in the greenhouse air at concentrations three times above the occupational exposure limit and was still detectable four days later

Persistence of malathion used in dengue control on household surfaces

ABSTRACT: Dengue is a viral infection transmitted by the mosquito Aedes aegypti. In Brazil, one of the insecticides used to control the mosquito is malathion, which can be diluted in vegetable oil (1:2 v/v). The purpose of this study was to understand the persistence of malathion on different surfaces and soil. Surfaces were contaminated by malathion and then washed with water and soap. The water used to clean the surfaces was extracted and analyzed by gas chromatography with an FID detector. Soil samples received malathion 14C-TG diluted in vegetable oil (1:2 v/v) and were analyzed zero, 3, 7, 18, 32, 60, 120, 240, and 360 days after the application in a liquid scintillation analyzer. Results showed a high persistence of malathion on porous surfaces. Moreover, it did not degrade in the soil for the first 120 days