Assessing the feasibility of sugarcane bagasse as an alternative solid support for chlorpyrifos determination in tomato.

The feasibility of sugarcane bagasse to be employed as an alternative solid support for clean-up is presented during the development and validation of an analytical method to determine chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate) (CP) in tomato by HPLC-DAD. The efficiency of the method consisting of ultrasonic assisted extraction with acetonitrile and dispersion with salts, followed by dispersive phase extraction with powdered sugarcane bagasse is presented for three spiking levels relating to the established CP maximum residue limit (MRL) for industrial tomato in Brazil, 0.5 mg kg-1 (½ MRL, MRL and 2 MRL). Satisfactory results were obtained in terms of trueness (recovery range: 76.5-120.1%), intermediate precision (1.0-5.2%) and repeatability (4.7-12.8%), expressed as relative standard deviation. The proposed method has a limit of quantification of 0.25 mg kg-1 and could be deployed as cost effective routine analysis to monitor CP in tomato samples in processed food industries.

Determination of organochlorine priority substances in fish tissue: Optimisation of the clean-up step balancing removal of lipids with analytes' recovery.

Quality-assessed analytical methods are required to determine organic priority substances (PS) in biota for the monitoring of the water status according to the EU Water Framework Directive. Although the literature describes several analytical methods to determine these substances in fish, discussion about the efficiency of the clean-up procedures to remove the lipids in the final organic extract (and decrease the disturbance of co-extractives at the detection step) is scarce. This work highlights the results of the development of an analytical method for organochlorines in fish tissue focused on the optimisation of the clean-up step in order to obtain a final extract with the lowest amount of lipids. The efficiency of the purification of the final extract was assessed by quantifying the removal of co-extractives gravimetrically, by considering the sensitivity of the gas chromatography-mass spectrometry (GC-MS) method for the analytes and by assessing the analytes' recovery. An analytical method based on accelerated solvent extraction followed by gel permeation chromatography and dual solid phase extraction (as clean-up steps) and quantification via isotope dilution GC-MS was applied to the analysis of seven PS [α-, ß-, γ- and δ-hexachlorocyclohexane (HCH) isomers, pentachlorobenzene (PeCB), hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD)]. A preliminary validation of the method was carried out with satisfactory results for all analytes in terms of intermediate precision (2.9-9.4%, except 11.8% for ß-HCH). Repeatability values were satisfactory for α-, γ-HCH, PeCB and HCB (4.3-6.9%), while the obtained results for ß-, δ-HCH and HBCD showed the need for further optimisation. Trueness was within the target performance (recovery range: 96.0-107.5%) for all analytes except ß- and δ-HCH. Limits of quantification between 0.5 and 3.3 ng/g wet weight were achieved, depending on the analytes. The proposed method can be employed to determine the mentioned PS in fish tissue with up to approximately 6% lipid content. The presented results show the challenges in establishing an analytical method which aims at balancing the required accuracy with the routine applicability (and a minimised impact on the detection system) as needed in the context of environmental monitoring.

Influence of physical activity in the intake of trihalomethanes in indoor swimming pools.

This study describes the relationship between physical activity and intake of trihalomethanes (THMs), namely chloroform (CHCl3), bromodichloromethane (CHCl2Br), dibromochloromethane (CHClBr2) and bromoform (CHBr3), in individuals exposed in two indoor swimming pools which used different disinfection agents, chlorine (Cl-SP) and bromine (Br-SP). CHCl3 and CHBr3 were the dominant compounds in air and water of the Cl-SP and Br-SP, respectively. Physical exercise was assessed from distance swum and energy expenditure. The changes in exhaled breath concentrations of these compounds were measured from the differences after and before physical activity. A clear dependence between distance swum or energy expenditure and exhaled breath THM concentrations was observed. The statistically significant relationships involved higher THM concentrations at higher distances swum. However, air concentration was the major factor determining the CHCl3 and CHCl2Br intake in swimmers whereas distance swum was the main factor for CHBr3 intake. These two causes of THM incorporation into swimmers concurrently intensify the concentrations of these compounds into exhaled breath and pointed to inhalation as primary mechanism for THM uptake. Furthermore, the rates of THM incorporation were proportionally higher as higher was the degree of bromination of the THM species. This trend suggested that air-water partition mechanisms in the pulmonary system determined higher retention of the THM compounds with lower Henry's Law volatility constants than those of higher constant values. Inhalation is therefore the primary mechanisms for THM exposure of swimmers in indoor buildings.

Influence of sugar cane vinasse on the sorption and degradation of herbicides in soil under controlled conditions.

This study reports the influence of sugar cane vinasse on the persistence, sorption and leaching potential of diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea), hexazinone (3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4-dione) and tebuthiuron (1-(5-tert-butyl-1,3,4-thiadiazol-2-yl)-1,3-dimethylurea) in both a clay and sandy soil from a tropical area of Brazil. The experiments were conducted out under controlled laboratory conditions. The addition of sugarcane vinasse to soil influenced the persistence and sorption of the herbicides in both the studied clay and sandy soils, with a considerable decrease in the diuron DT50 values in clay soil. The Ground Water Ubiquity Score (GUS) Index classifies the herbicides as leachers in both soils and treatments, with the exception of diuron, which is classified as a non-leacher in clay soil-vinasse and as a transient herbicide in sandy soil. These results suggest that special attention should be given to areas such as those where the sandy soil was collected in this study, which is a recharge area of the Guarani Aquifer and is likely to experience groundwater contamination due to the high leaching potential of the applied pesticides.

Método analítico para identificar plaguicidas en el aire atmosférico / Analytical method to identify pesticides in the atmosphere

La volatilización puede ser una importante ruta de distribución de plaguicidas en el medio ambiente y la toma de muestras de aire para la cuantificación de plaguicidas es crítica para el proceso analítico.

Método analítico para identificar plaguicidas en el aire atmosférico / Analytical method to identify pesticides in the atmosphere

La volatilización puede ser una importante ruta de distribución de plaguicidas en el medio ambiente y la toma de muestras de aire para la cuantificación de plaguicidas es crítica para el proceso analítico.

Trihalomethanes in chlorine and bromine disinfected swimming pools: air-water distributions and human exposure.

This first study of trihalomethanes (THMs) in swimming pools using bromine agents for water disinfection under real conditions shows that the mixtures of these compounds are largely dominated by bromoform in a similar process as chloroform becomes the dominant THM in pools disinfected with chlorine agents. Bromoform largely predominates in air and water of the pool installations whose concentration changes are linearly correlated. However, the air concentrations of bromoform account for about 6-11% of the expected concentrations according to theoretical partitioning defined by the Henry law. Bromoform in exhaled air of swimmers is correlated with the air concentrations of this disinfectant by-product in the pool building. Comparison of the THM exhaled air concentrations between swimmers and volunteers bathing in the water without swimming or standing in the building outside the water suggest that physical activity enhance exposure to these disinfectant by-products. They also indicate that in swimming pools, besides inhalation, dermal absorption is a relevant route for the incorporation of THMs, particularly those with lower degree of bromination.

Validação e aplicação de método para análise de pesticidas em água para consumo humano de Dourados (MS) por CLAE/UV e CG/DTE / Validation and application of method for pesticides analysis in drinking water from Dourados/MS-Brazil) by HPLC-UV and GC-TSD

O uso inadequado de pesticidas na agricultura tem sido apontado como fonte de risco para a saúde humana e para o ambiente. Considerando que os recursos hídricos são os principais destinos desses compostos após a aplicação, este trabalho apresenta a otimização e validação de dois métodos analíticos simples e efi cientes para a determinação de pesticidas em águas superfi ciais e subterrâneas. Foram selecionados os pesticidas mais aplicados no município de Dourados, (Mato Grosso – Brasil) com intensa atividade agrícola. Efetuou-se a pré-concentração por extração em fase sólida com cartucho C18 (500 mg) e eluição com metanol para as amostras analisadas por cromatografi a a líquido de alta eficiência com detector espectrofotométrico na região do ultravioleta (CLAE/UV) (2,4-D e 2,4-DCF) e com acetato de etila:diclorometano (1:1, v/v) para as analisadas por cromatografi a a gás com detector termiônico específi co (CG/DTE) (atrazina, DIA, DEA, trifluralina e parationa metílica). Os métodos apresentaram exatidão (76-107%) e precisão (<12%) satisfatórias para as substâncias nos níveis de fortifi cação selecionados, exceto para DIA (<51%), assim como para o estudo de estabilidade dos pesticidas (-20ºC por até 21 dias). Os limites de quantificação dos métodos (0,22 - 0,48 μg L-1) estão de acordo com a legislação brasileira vigente para pesticidas em água. Embora somente o 2,4-D tenha sido detectado em dois pontos de coleta no período estudado, alerta-se para a necessidade de avaliação sistemática da presença de pesticidas em água para consumo humano, particularmente, em regiões com intensa atividade agrícola. Tal monitoramento pode fornecer subsídios para políticas públicas ambientais.

Validation and application of an analytical method for determining pesticides in the gas phase of ambient air.

A method for determining atmospheric concentrations of eight pesticides applied to corn and soybean crops in Mato Grosso state, Brazil is presented. The method involved a XAD-2 resin cartridge coupled to a low volume air pump at 2 L min⁻¹ over 8 hours. Pesticides were recovered from the resin using sonication with n-hexane:ethyl acetate and determined by GC-MS. Good accuracy (76-128%) and precision (CV < 20%) were obtained for atrazine, chlorpyrifos, alpha- and beta-endosulfan, endosulfan sulfate, flutriafol, malathion, metolachlor and permethrin. Method detection ranged from 9.0 to 17.9 ng m⁻³. This method was applied to 61 gas phase samples collected between December 2008 and June 2009. Atrazine and endosulfan were detected both in urban and rural areas indicating the importance of atmospheric dispersion of pesticides in tropical areas. The simple and efficient extraction method and sampling system employed was considered suitable for identifying pesticides in areas of intense agricultural production.

What's in the pool? A comprehensive identification of disinfection by-products and assessment of mutagenicity of chlorinated and brominated swimming pool water.

BACKGROUND: Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in the water and related that to mutagenicity. OBJECTIVES: We performed a comprehensive identification of DBPs and disinfectant species in waters from public swimming pools in Barcelona, Catalonia, Spain, that disinfect with either chlorine or bromine and we determined the mutagenicity of the waters to compare with the analytical results. METHODS: We used gas chromatography/mass spectrometry (GC/MS) to measure trihalomethanes in water, GC with electron capture detection for air, low- and high-resolution GC/MS to comprehensively identify DBPs, photometry to measure disinfectant species (free chlorine, monochloroamine, dichloramine, and trichloramine) in the waters, and an ion chromatography method to measure trichloramine in air. We assessed mutagenicity with the Salmonella mutagenicity assay. RESULTS: We identified > 100 DBPs, including many nitrogen-containing DBPs that were likely formed from nitrogen-containing precursors from human inputs, such as urine, sweat, and skin cells. Many DBPs were new and have not been reported previously in either swimming pool or drinking waters. Bromoform levels were greater in brominated than in chlorinated pool waters, but we also identified many brominated DBPs in the chlorinated waters. The pool waters were mutagenic at levels similar to that of drinking water (approximately 1,200 revertants/L-equivalents in strain TA100-S9 mix). CONCLUSIONS: This study identified many new DBPs not identified previously in swimming pool or drinking water and found that swimming pool waters are as mutagenic as typical drinking waters.

Short-term changes in respiratory biomarkers after swimming in a chlorinated pool.

BACKGROUND: Swimming in chlorinated pools involves exposure to disinfection by-products (DBPs) and has been associated with impaired respiratory health. OBJECTIVES: We evaluated short-term changes in several respiratory biomarkers to explore mechanisms of potential lung damage related to swimming pool exposure. METHODS: We measured lung function and biomarkers of airway inflammation [fractional exhaled nitric oxide (FeNO), eight cytokines, and vascular endothelial growth factor (VEGF) in exhaled breath condensate], oxidative stress (8-isoprostane in exhaled breath condensate), and lung permeability [surfactant protein D (SP-D) and the Clara cell secretory protein (CC16) in serum] in 48 healthy nonsmoking adults before and after they swam for 40 min in a chlorinated indoor swimming pool. We measured trihalomethanes in exhaled breath as a marker of individual exposure to DBPs. Energy expenditure during swimming, atopy, and CC16 genotype (rs3741240) were also determined. RESULTS: Median serum CC16 levels increased from 6.01 to 6.21 microg/L (average increase, 3.3%; paired Wilcoxon test p = 0.03), regardless of atopic status and CC16 genotype. This increase was explained both by energy expenditure and different markers of DBP exposure in multivariate models. FeNO was unchanged overall but tended to decrease among atopics. We found no significant changes in lung function, SP-D, 8-isoprostane, eight cytokines, or VEGF. CONCLUSIONS: We detected a slight increase in serum CC16, a marker of lung epithelium permeability, in healthy adults after they swam in an indoor chlorinated pool. Exercise and DBP exposure explained this association, without involving inflammatory mechanisms. Further research is needed to confirm the results, establish the clinical relevance of short-term serum CC16 changes, and evaluate the long-term health impacts.

New method for determination of trihalomethanes in exhaled breath: applications to swimming pool and bath environments.

A method for the estimation of the human intake of trihalomethanes (THMs), namely chloroform, bromodichloromethane, dibromochloromethane and bromoform, during showering and bathing is reported. The method is based on the determination of these compounds in exhaled breath that is collected by solid adsorption on Tenax using a device specifically designed for this purpose. Instrumental measurements were performed by automatic thermal desorption coupled to gas chromatography with electron capture detection. THMs in exhaled breath samples were determined during showering and swimming pool attendance. The levels of these compounds in indoor air and water were also determined as reference for interpretation of the exhaled breath results. The THM concentrations in exhaled breath of the volunteers measured before the exposure experiments showed a close correspondence with the THMs levels in indoor air where the sampler was located. Limits of detection in exhaled breath were dependent on THM analytes and experimental sites. They ranged between 170 and 710 ng m(-3) in the swimming pool studies and between 97 and 460 ng m(-3) in the showering studies. Application of this method to THMs determination during showering and swimming pool activities revealed statistically significant increases in THMs concentrations when comparing exhaled breath before and after exposure.

Human health risk assessment of environmental exposure to organochlorine compounds in the Catalan stretch of the Ebro River, Spain.

In this study, the environmental impact and human health risks associated with exposure to organochlorine compounds (OCs) through soils and tap water in the Catalan stretch of the Ebro River, Spain, were investigated. The concentrations of polychlorinated biphenyls, hexachlorocyclohexanes, as well as DDT and derivates, were determined. Relatively low levels of these pollutants were observed, with mean concentrations ranging between 0.51-315.8 lg/kg and 0.05-74.6 ng/L in soil and tap water, respectively. These values are similar to those found in a number of recent surveys over the world. In spite of the presence of a chlor-alkali plant located upstream the Ebro River, which could mean a potential source of pollution, the current levels of OCs should not mean significant additional health risks for the local population.

Residues of organochlorine pesticides and PCBs in some Brazilian municipal solid waste compost.

Persistent organic pollutants (POPs), organochlorine pesticides and polychlorinated biphenyls (PCBs), listed as per the Stockholm Convention (alpha -HCH, beta -HCH, gamma -HCH, p,p'-DDT, o,p'-DDT, p,p'-DDD, p,p'-DDE, aldrin, endrin, dieldrin, PCBs 28, 52, 118, 138, 153, and 180), were analyzed in municipal solid waste (MSW) compost samples from three different Brazilian composting plants located in three São Paulo State cities: Araras, Araraquara and São Paulo (Vila Leopoldinha). Quantitative and qualitative analyses were carried out using gas chromatography electron capture detection (GC-ECD) and gas chromatography mass spectrometry (GC-MS) (Ion Trap, electron impact ionization), respectively. The samples were analyzed in triplicate and the target POPs were not detected by GC-ECD. Twelve pollutants were identified in two samples when qualitative analysis (GC-MS) was used (beta -HCH, gamma -HCH, p,p'-DDT, o,p'-DDT, p,p'-DDD, and p,p'-DDE, PCBs 28, 118, 138, 153 and 180). The composting process has advantages such as urban solid waste reduction and landfill life-span increase, however the MSW compost quality, which can be utilized for agricultural purposes, should be evaluated and be controlled. This kind of study is the first step in making available information to answer questions regarding MSW compost for sustainable agricultural use, such as the pollutants accumulation in soil and in groundwater, and plants uptake.

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