Effects Of Pesticide Contamination Research Articles

Relación de díeldrin y propiedades del suelo en la Comarca Lagunera, México

Recientemente se han reportado residuos de plaguicidas en el ambiente como resultado de las aplicaciones de estos productos durante varias décadas. A nivel mundial se presentan problemas atribuidos a los efectos de la contaminación por plaguicidas sobre los recursos naturales; sin embargo, en México, no existen suficientes estudios de contaminación por plaguicidas. El objetivo fue evaluar la presencia de plaguicidas en suelos de siete localidades de cinco Municipios de la Comarca Lagunera en el estado de Coahuila, se realizó un muestreo de suelos a cinco profundidades (0-8, 8-23, 23-38, 38-53 y 53-68 cm) a razón de una muestra compuesta por hectárea para determinar el grado de contaminación del suelo por plaguicidas. Se utilizó el método soxhlet para la extracción de plaguicidas en la muestra y un Kuderna Danish, para la concentración. Se utilizó un cromatografó de gases. Se encontró que el díeldrin fue el único plaguicida organoclorado presente en los suelos estudiados; las capas superficiales del suelo (0-8 y 8-23 cm) mostraron las mayores concentraciones de díeldrin. El contenido de materia orgánica, el porcentaje de arcilla y el pH del suelo fueron las características que más influencia tuvieron sobre la concentración del díeldrin en el suelo, presentando los coeficientes de determinación más altos (r2= 0.99, 0.84 y 0.96, respectivamente). En los suelos de los predios particulares estudiados, se observaron las mayores concentraciones de díeldrin en la capa superficial (0-23 cm), esto en relación con los ejidos evaluados; estos valores fueron del orden de 2.57 y 1.22 ng g-1, respectivamente.

Atrazine, chlorpyrifos, and iprodione effect on the biodiversity of bacteria, actinomycetes, and fungi in a pilot biopurification system with a green cover

ABSTRACTThe use of biopurification systems can mitigate the effects of pesticide contamination on farms. The primary aim of this study was to evaluate the effect of pesticide dissipation on microbial communities in a pilot biopurification system. The pesticide dissipation of atrazine, chlorpyrifos and iprodione (35 mg kg−1 active ingredient [a.i.]) and biological activity were determined for 40 days. The microbial communities (bacteria, actinomycetes and fungi) were analyzed using denaturing gradient gel electrophoresis (DGGE). In general, pesticide dissipation was the highest by day 5 and reached 95%. The pesticides did not affect biological activity during the experiment. The structure of the actinomycete and bacterial communities in the rhizosphere was more stable during the evaluation than that in the communities in the control without pesticides. The rhizosphere fungal communities, detected using DGGE, showed small and transitory shifts with time. To conclude, rhizosphere microbial communities were not affected during pesticide dissipation in a pilot biopurification system.

Monitoring Pesticide Residues in Surface and Ground Water in Hungary: Surveys in 1990–2015

Over 2000 surface, ground and raw drinking water samples have been analyzed in the frame of different monitoring projects in Hungary and watercourses in neighboring countries between 1990 and 2015. Effects of pesticide contamination on ecological farming and drinking water supply have been assessed. Main water pollutant ingredients of agricultural origin in Hungary are herbicides related to maize production. After EU pesticide re-registration, diazinon, atrazine, and trifluralin gradually disappeared as contaminants. High levels of water soluble pollutants (e.g., acetochlor) in surface water result in temporarily enhanced levels in raw drinking water as well. Extreme levels observed for herbicide residues were of agrochemical industrial origin.

Effects of Pesticide-Contamination on Population and Activity of Bacteria in Purple Paddy Soil

The effect of pesticides on microbial in soil is susally used as an important guide line for estimating the ecological safty of soil. Effects of pesticide-contamination on population and activity of bacteria were investigated in purple paddy soil by in door culture method. The results showed that the population and activity of methanogens was stimulated slightly by adding carbofuran or butachlor in paddy soil, but significantly inhibited by adding of butachlor (10mg kg-1), carbofuran (0.5mg kg-1) and carbendazim (10mg kg-1) in paddy soil. At 7th day the inhibition reached the maximum and then gradually reduced down to the level in control. 1mg kg-1 carbufuran and butachlor markedly stimulate the populations and activity of soil methane-producing bacteria, soil anti-nitrifying bacteria, soil nitrogen-fixing bacteria, and soil sulfate-reducing bacteria in purple paddy rice soils. Higher concentration carbufuran and butachlor significantly inhibite the populations and activity of above bacteria. Then the inhibition effects of the contaminants were gradually attenuating. The population and activity of above bacteria were inhibited by different level carbendazim.

Review of hydrologic assessment models for predicting pesticide leaching in Nigeria

The need to evaluate the potential risks of pesticides usage that may lead to contamination of water resources has been the reason behind the development of models for predicting pesticide leaching in soils and watershed areas. Various assessment models have been developed in the past. For example, the vulnerability of groundwater to pesticide leaching may be evaluated by indices and overlay-based methods, by statistical analyses of monitoring data, or by using process-based models of pesticide fate. Most of these models have been applied in various parts of the world but with little or none applicability in Nigeria. Since Nigeria is an agrarian country whose soils and water resources have suffered severely from the effects of pesticide contamination, the need to inform decision on applicability of some of these models becomes paramount. This paper thus provide a descriptive synthesis of some of the models used in predicting pesticide leaching in underground water and make recommendation for their usage in assessing groundwater contamination effects resulting from agricultural processes in Nigeria. Key words: Groundwater, model, pesticide, hydrologic, simulation, management.

Molecular identification and expression study of differentially regulated genes in the Pacific oyster Crassostrea gigas in response to pesticide exposure

The effects of pesticide contamination on the metabolism of marine molluscs are poorly documented. We investigated the response of a marine bivalve, the Pacific oyster, Crassostrea gigas, using a suppression subtractive hybridization method to identify up- and down-regulated genes after a 30-day exposure period to herbicides (a cocktail of atrazine, diuron and isoproturon, and to the single herbicide glyphosate). A total of 137 unique differentially expressed gene sequences was identified, as well as their associated physiological process. The expression of 18 of these genes was analyzed by RT-PCR under laboratory experimental conditions. The metabolic functions they are associated with include xenobiotic detoxification, energy production, immune system response and transcription. This study provides a preliminary basis for studying the response of marine bivalves to long-term herbicide exposure in terms of regulated gene expression and characterizes new potential genetic markers of herbicide contamination.

Effects of Pesticide Contamination from Rice Fields on Stream Benthic Arthropods.

Effects of Pesticide Contamination from Rice Fields on Stream Benthic Arthropods.