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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.

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Dithiocarbamates are a class of fungicides extensively used in many crops worldwide. The current residue definition of dithiocarbamates in food for compliance with maximum residue limits, at national and international levels, is total residues arising from the use of any or each dithiocarbamate fungicide, determined as CS(2). The analytical method most frequently used to analyze dithiocarbamate residues in food for monitoring purposes was proposed more than 30 years ago. In this method, total dithiocarbamates are decomposed to CS(2), which is purified and reacted with a cupric reagent. The yellow complex formed is quantified by spectrophotometry. In this paper, a new reaction system for the purification and complexation of CS(2) is proposed. The new system is less fragile than the traditional design, is easier to assemble, and allows for a higher sample throughput, in addition to being of low cost. Recovery of added mancozeb, thiram, or ziram (0.15-8.0 mg/kg) in rice, beans, apple, banana, orange, papaya, tomato, cucumber, and potato ranged from 82 to 120%, with relative standard deviations from 0 to 10% (n = 3 or 5). Analysis of apple, tomato, and papaya samples with field-incurred dithiocarbamate residues showed comparable results using both the traditional and the new reaction systems.

In this study, the knowledge, attitudes and practices regarding pesticide use and the levels of exposure of farmers and residents to organophosphorous and/or carbamates pesticides were evaluated in two rural settings in Brazil. A questionnaire was completed by 112 farm workers aged ≥18 years. Almost all farmers acknowledged that pesticides were potentially harmful to their health (87.5%); however, over half rarely (48.2%) or never (7.2%) used personal protective devices (PPDs). An association was found (p = 0.001) between the work regimen and the use of PPDs, with more frequent equipment use among hired laborers than those involved in family agriculture. A significant correlation (p = 0.027) was found between the reporting of adverse symptoms and the use of backpack sprayers. Mean AChE activities of farmers (n = 64) and residents (n = 18) during the exposure and non-exposure periods were significantly lower than their control groups. Mean BChE activities of farmers and residents were significantly lower than their controls during the exposure period. Among the 60 farmers that had blood samples collected in both the exposure and non-exposure (baseline) periods, 10 (16.7%) had AChE depletion of over 30% during the exposure period compared with the baseline level. Six residents living on the same farms also presented this depletion. AChE was over 30% higher than the baseline level for 19 farmers (31.7%), indicating a reboot effect. Special education programs are needed in these regions to promote the safe use of pesticides in the field to decrease the risks from exposure to pesticides for farmers, and from secondary exposure to these compounds for their families.