Environmental dynamics of pesticides in the drainage area of the São Lourenço River headwaters, Mato Grosso State, Brazil

Abstract

Este estudo avaliou a dinâmica de pesticidas na cabeceira de drenagem do Rio São Lourenço, Mato Grosso, Brasil. Os pesticidas atrazina, flutriafol, metolacloro, α-e β-endosulfan e os metabólitos endosulfan sulfato, desetilatrazina e desisopropilatrazina foram determinados em amostras de água (superficial, subterrânea, de chuva e de escoamento superficial) e de sedimento (de escoamento superficial e de fundo) coletadas entre agosto de 2009 e julho de 2010 utilizando SPE-GC/MS-SIM (extração em fase sólida-cromatografia gasosa acoplada à espectrometria de massas em modo de monitoramento seletivo de íons). Os resultados demonstraram que o escoamento superficial e a deposição atmosférica são processos importantes de entrada de pesticidas na água superficial, principalmente por pesticidas altamente adsorvidos nas partículas de sedimento, cuja concentração máxima foi de 2218 mg kg -1 para β-endosulfan, e dissolvidos em água com concentração máxima de 28,3 mg L -1 para atrazina. Endosulfan sulfato, atrazina e metolacloro foram os compostos detectados com maior frequência. A lixiviação foi uma via importante de transporte devido ao comportamento hídrico do solo e ao baixo nível do lençol freático, levando à contaminação de águas subterrâneas bem como de águas superficiais devido ao fluxo em subsuperfície.This study assessed the environmental dynamics of pesticides in the São Lourenço River headwaters, Mato Grosso State, Brazil. The pesticides atrazine, flutriafol, metolachlor, α-and β-endosulfan and the metabolites endosulfan sulfate, desethylatrazine and desisopropylatrazine were determined in water (rain, surface, ground and runoff) and in sediment (runoff and bottom) samples, collected from August 2009 to July 2010, by SPE-GC/MS-SIM (solid phase extractiongas chromatography/mass detector with selected ion monitoring). Runoff and rain atmospheric deposition showed to be important pathways for surface water contamination mainly by highly sorbed pesticides found in sediment with maximum concentration of 2218 mg kg -1 for β-endosulfan, and in water with maximum concentration of 28.3 mg L -1 for atrazine. Endosulfan sulfate, atrazine and metolachlor were the compounds with the highest frequency of detection. Leaching was an important process of off-site transport mainly due to the hydric behavior of soil and the low depth of water table, leading to contamination of groundwater as well as surface water via subsurface flow.Keywords: pesticide, runoff, leaching, off-site transport, water contamination IntroductionAgricultural production is an important source of income, especially in developing countries where several economy sectors such as the tertiary sector benefit from this activity. However, the potential harm to the environment grows with increases in production. In Brazil, the highly technological agricultural production is responsible for a great portion of Brazilian export revenue. This type of production demands a great amount of inputs such as pesticides and fertilizers.Pesticides used in agriculture, after reachi...

The Brazilian Cerrado: assessment of water and soil degradation in catchments under intensive agricultural use

“…Nogueira et al (2012) found very high maximum concentrations of atrazine in groundwater (18.9 μg l À1 ) and surface water (9.3 μg l À1 ). Similarly, Casara et al (2012) detected atrazine in water runoff samples, with an extremely high maximum concentration of 28.3 μg l À1 ; most frequently, the substance was detected in rainwater samples, as supported by the study of Moreira et al (2012), in which extremely high concentrations of atrazine (75.43 μg l À1 ), monocrotofos (41.35 μg l À1 ) and flutriafol (29.64 μg l À1 ) were detected. Similarly, Casara et al (2012) detected atrazine in water runoff samples, with an extremely high maximum concentration of 28.3 μg l À1 ; most frequently, the substance was detected in rainwater samples, as supported by the study of Moreira et al (2012), in which extremely high concentrations of atrazine (75.43 μg l À1 ), monocrotofos (41.35 μg l À1 ) and flutriafol (29.64 μg l À1 ) were detected.…”

“…Pesticide concentrations and detection frequencies were highest for atrazine and flutriafol from March to May, when a second crop (soybean, corn or cotton) is typically grown (Casara et al, 2012). Dores et al (2008) temporarily linked the highest detection frequencies of herbicides in groundwater and surface water samples to the application dates of pesticides in the rainy season.…”

Contaminantes emergentes em matrizes aquáticas do Brasil: cenário atual e aspectos analíticos, ecotoxicológicos e regulatórios

“…Os estudos realizados em amostras de águas subterrâneas estão concentrados no Estado do Mato Grosso, [56][57][58][59][60]73 . A atrazina e o aloclor foram os pesticidas mais frequentemente dectados dentre os 27 que foram monitoramento nas águas subterrâneas da Slovenia de acordo com Gotvajn e colaboradores.…”

Predictive quality of 26 pesticide risk indicators and one flow model: A multisite assessment for water contamination

“…Our results should serve to discourage this misuse of simple indicators assessing management. On the other side of the gradient of complexity, the mechanistic model MACRO (Larsbo et al, 2005) integrating precisely the processes of vertical transfer (Casara et al, 2012) logically yields the best results, although it is not always the most complex prediction tool that are the most accurate (Makowski et al, 2009). Although MACRO was not calibrated, these results were obtained for one set of parameters over seven for La Jaillière and four for Le Magneraud site, with soil description of Arvalis -Institut du Végétal, and the automatic chain of calculation developed by Agrosolution.…”