a b s t r a c tA total of 13,556 samples of 22 fruit and vegetable crops, rice, and beans were analyzed within two Brazilian pesticide residue monitoring programs between 2001 and 2010. Pesticide residues were found in 48.3% of the samples, and 13.2% presented some irregularity, mostly non-authorized active ingredient use. Less than 3% of the samples had residue levels above the MRL. Apple, papaya, sweet pepper and strawberry were the crops with the higher percentages of positive samples (about 80%). Dithiocarbamates and organophosphorus compounds were found in 41.6% and 30.8% of the samples, respectively. Carbendazim and chlorpyrifos were the pesticides most found (26.7 and 16.1% of positive samples, respectively). Almost half of the samples analyzed had multiple residues (up to 10 residues), with multiple residues most common in samples of apple, sweet pepper and tomato. About 8% of positive samples contained up to four residues of the same chemical class, mainly organophosphorus compounds (18.6%, mostly in apple) and triazoles (16.1%, mostly in papaya and grape). In general, the scenario of pesticide residues in foods investigated within the Brazilian governmental monitoring programs in the last decade is similar to what has been found in other countries. However, the use of non-authorized active ingredients is a common practice among the farmers in the country, a problem that the government authorities have been trying to solve. A preliminary cumulative acute exposure assessment for organophosphates and carbamates in apple has shown that the intake by individuals 10 years old accounts for 100% of the acephate ARfD, indicating a need to further investigate the exposure through the consumptions of other crops and group of pesticides, mainly for children.

A multiresidue method for the determination of 46 pesticides in fruits was validated. Samples were extracted with acidified ethyl acetate, MgSO4 and CH3COONa and cleaned up by dispersive SPE with PSA. The compounds were analysed by GC-FPD, GC-μECD or LC-MS/MS, with LOQs from 1 to 8 μg/kg. The method was used to analyse 238 kaki, cashew apple, guava, and peach fruit and pulp samples, which were also analysed for dithiocarbamates (DTCs) using a spectrophotometric method. Over 70% of the samples were positive, with DTC present in 46.5%, λ-cyhalothrin in 37.1%, and omethoate in 21.8% of the positive samples. GC-MS/MS confirmed the identities of the compounds detected by GC. None of the pesticides found in kaki, cashew apple and guava was authorised for these crops in Brazil. The risk assessment has shown that the cumulative acute intake of organophosphorus or pyrethroid compounds from the consumption of these fruits is unlikely to pose a health risk to consumers.

Recebido em 16/9/08; aceito em 11/2/09; publicado na web em 23/7/09 CHEMICAL DIETARY EXPOSURE AND THE RISKS TO HUMAN HEALTH. Humans are exposed to a variety of chemicals from the consumption of food, including undesirable compounds such as pesticides and mycotoxins. Chemical human risk assessment is a process intended to estimate the risk to a given population from the exposure to a chemical (or to a chemical group having the same mechanism of action). The process consists of four steps, namely hazard identification, hazard characterization, exposure assessment and risk characterization. Chemical dietary risk assessment is an essential procedure to establish safe food standards. In this review the tools and data sources currently used in the risk assessment process will be discussed.Keywords: food; chemical exposure; dietary risk assessment. INTRODUÇÃONos alimentos que consumimos está presente uma grande variedade de substâncias químicas, como aquelas essenciais para a manutenção da saúde, como vitaminas, minerais e proteínas, e algumas potencialmente tóxicas, como micotoxinas, resíduos de pesticidas, aditivos e metais pesados. A falta de algum nutriente ou a presença excessiva no alimento de substâncias tóxicas pode significar um risco à saúde humana.A preocupação com a presença de substâncias químicas nos alimentos iniciou-se na década A avaliação do risco objetiva estimar o risco a um dado organismo alvo, sistema ou (sub)população, incluindo a identificação das incertezas esperadas, após a exposição a um agente particular, levando em consideração as características inerentes ao agente e as do sistema alvo.3 Avaliar o risco causado pela exposição humana a substâncias químicas na dieta é amplamente reconhecido como um processo fundamental no desenvolvimento de padrões alimentares seguros. 4 A avaliação é conduzida, por exemplo, pelos governos durante o processo de registro de aditivos alimentares ou de substâncias que serão utilizadas no manejo agropecuário, como pesticidas e drogas veterinárias. No caso de contaminantes presentes nos alimentos, os estudos subsidiam ações gerenciais que levem ao controle da contaminação e diminuição da exposição humana.No Brasil, a Agência Nacional de Vigilância Sanitária (ANVISA) é responsável pelo processo de registro de aditivos, pesticidas e drogas veterinárias e pela condução de avaliação do risco da exposição humana a estas substâncias e a contaminantes em alimentos. Enquanto a avaliação do risco é um processo de base científica, o gerenciamento do risco envolve tomada de decisões pelas agências reguladoras que levam em consideração, além de informações técnicas relevantes relacionadas ao dano à saúde e ao risco, fatores políticos, sociais e econômicos. A troca de informações sobre o risco entre avaliadores, gerenciadores, mídia, grupos de interesse e público em geral se dá no âmbito da comunicação de risco.3 A avaliação, o gerenciamento e a comunicação do risco são processos que interagem entre si, sendo partes de um processo maior, a análise do risco (Figura 1) Neste tr...

In this study ready-to-eat food samples were collected in the production line of the university restaurant of the University of Brasilia, Brazil, which serves non-vegetarian and vegetarian meals daily. Samples were analysed for the presence of ten organophosphorus insecticides (OPs) by GC/FPD, after extraction with ethyl acetate and anhydrous sodium sulfate (LOQ = 0.002 mg kg(-1)), and for dithiocarbamate fungicides, as CS(2), using the spectrophotometric method (LOQ = 0.05 mg kg(-1)). About 43% of the 175 samples analysed contained at least one OP compound at levels up to 1.83 mg kg(-1). Methamidophos was the compound most detected (37.7%), present in most of the soup, soybean and salad samples. No OP residues were found in fruit juice, beans and bran rice samples. The cumulative acute intake of OPs was estimated using methamidophos and acephate as index compounds (IC). The total cumulative intake represented 9.1% and 47.7% of the methamidophos ARfD for the non-vegetarian and vegetarian diets, respectively. When acephate was used as IC, the total intakes represented 20.7% and 116% of the ARfD for the non-vegetarian and vegetarian diets, respectively. Dithiocarbamates were detected in 70% of the 177 samples analysed, at levels up to 0.51 mg kg(-1) CS(2); all salad samples were positive and no residues were found in fruit juice. The chronic intake of dithiocarbamates represented 8.6 and 8.9% of the ADI (mancozeb) for the vegetarian and non vegetarian diets, respectively.

Field trials were conducted in commercial agricultural areas in Brazil to determine the variability of residues of parathion methyl, diazinon and methidathion in individual units of large crops treated twice with a mixture of the three pesticides. Over 120 random samples were collected, extracted with ethyl acetate and residues determined by GC/FPD. The recoveries and their coefficient of variation were, in general, within the acceptable levels during sample analyses. Residues in papaya and mango were not affected by the position of the fruits in the plant, apparently more or less exposed to the pesticides. Variability factor ?, defined as the 97.5th percentile divided by the mean of residues in all samples taken from a field ranged from 2.0-2.6. The variability of residues within the plant contributed to about 34-61% of the field variability. The results found in this study support the variability factor of 3 adopted by the FAO/WHO for the deterministic estimation of dietary acute intake of pesticides.