Polycyclic aromatic hydrocarbons from wood pyrolyis in charcoal production furnaces.

Polycyclic aromatic hydrocarbons (PAH) were measured in smoke samples from wood carbonization during charcoal production, in both particulate matter (PM) and gaseous phases. Samples were acquired using a medium-volume air sampler at 1.5 m distance from the furnace. Particle-bound PAH were collected on Fluoropore polytetrafluoroethylene filters and gas-phase PAH were collected into sorbent tubes with XAD-2 resin. PAH were extracted with dichloromethane-methanol and analyzed using gas chromatography-mass spectrometry. The results showed total emission from the furnace of 26 microg/m3 for the 16 PAH and 2.8 microg/m3 for the 10 genotoxic PAH (from fluoranthene to benzo[g,h,i]perylene). High emission of 16 PAH in the first 8 h of wood carbonization was detected (64 microg/m3; 56% of the total emission). Associated with PM, 11% of the total emission of 16 PAH (in both phases) and 60% of 10 genotoxic PAH were found. Relative ratios (for example, [Phe]/[Phe]+[Ant]) for the PAH of the same molecular weight were obtained and compared with the published data. The concentrations of benzo[a]pyrene equivalent (BaP(eq)) were estimated using the list of toxic equivalent factors suggested by . The values of 0.30 and 0.06 mg/m3 were obtained for the total concentrations of BaP(eq) in PM and gaseous phase, respectively.

Avaliação do potencial de contaminação de águas subterrãneas por pesticidas: comparação entre métodos de previsão de lixiviação / Assessment of groundwater contamination potential by pesticides: comparison among methods of leaching prediction

Este trabalho teve como objetivo comparar alguns modelos descritosna literatura (critérios de screening da EPA, índices GUS e LIX e modelos RF, AF e TLPI) para avaliação do potencial de lixiviação de pesticidas e a possibilidade de contaminação de água subterrãnea, inicialmente, a simbologia e as expressões matemáticas foram organizadas de modo a facilitar a identificação e o entendimento dos fatores considerados na construção de cada modelo. A aplicação e a comparação dos modelos foram realizadas a partir de dados da literatura (propriedades físico-química dos pesticidas, propriedades do solo e condições climáticas) para nove herbicidas (2,4-D, alaclor, atrazina, clomazona, fluazifop-p-butílico, metribuzim, picloram, simazina, trifluralina) registrados e mais usados na cultura de cana-de-açúcar no Brasil. Os resultados do potencial de lixiviação fornecidos pelos métodos não foram concordantes para alguns herbicidas, entretanto, a classificação de potencial de lixiviação apresentou-se muito semelhante para todos os produtos. As diferenças encontradas podem ser justificadas pelas singularidades e limitações inerentes à concepção de cada método. Os resultados demonstram que modelos mais simples podem ser úteis para avaliar o potencial de contaminação da águas subterrãnea em grandes áreas de monocultura, fornecendo subsídios para tomadas de decisões mais rápidas e eficientes pelos órgãos competentes

Fast chromatographic determination of polycyclic aromatic hydrocarbons in aerosol samples from sugar cane burning.

Sugar cane burning in Brazil causes remarkable amounts of organic compounds to be emitted amongst which the polycyclic aromatic hydrocarbons (PAHs) represent serious health hazards. Therefore, 24-h aerosol samples (< 10 microm aerodynamic diameter) were collected in Araraquara city (São Paulo state) during the harvest season using a Hi-Vol sampler. PAHs were recovered using an Accelerated Solvent Extractor and analyzed by low-pressure gas chromatography-ion trap mass spectrometry (LP-GC-IT-MS). The fully automated extraction process was performed in less than 25 min with a solvent consumption of approximately 20 ml. The use of a deactivated 0.6 m x 0.10 mm i.d. restrictor coupled to a 10 m wide-bore analytical column allowed most of the 16 PAHs in EPA's priority list to be identified and quantified in only 13 min. Concentrations of PAHs in Araraquara aerosols ranged between 0.5 and 8.6 ng m(-3).

Determination of butyltin compounds in surface sediments from the São Paulo State coast (Brazil) by gas chromatography-pulsed flame photometric detection.

Occurrence and the effects of butyltin compounds (BTs) have been studied for some years, mainly in countries of the Northern Hemisphere. Due to widespread use of tributyltin compounds (TBTs) and considering their deleterious effects, it is necessary to conduct studies on its occurrence, especially in the marine environment because of its excessive use in coatings of ship hulls to prevent fouling. Moreover, it was important to extend the evaluation to areas where there is no current information about their occurrence. The present work reports the occurrence of BTs in marine sediments of São Paulo state, Brazil. Commercial and leisure harbor sampling sites were selected because these areas are potentially exposed to BTs from antifouling paints used on ship hulls. Analytical conditions for organotin analysis in marine sediments were optimized for GC with pulsed flame photometric detection. Detection limits ranged from 8A to 66.3 ng g(-1) using a 610-nm filter, and the linearity range was 20-500 ng g(-1). Concentration levels of BTs were highest in Santos harbor (360 ng g(-1) TBT in average) and Guarujá marina (670 ng g(-1) TBT in average), which seems to be related to intensive boat traffic. Lower levels of BTs were observed in Cananéia, where only fishing boats are present (50 ng g(-1) TBT in average).