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Exposure of Channa striatus over 24 h to 40% and 80% of the LC50;24h of the three pyrethroids cypermethrin, permethrin, and fenvalerate did not cause any significant changes in the levels of total protein and free amino acids in the liver and muscle tissues of the fish. After 96 h exposure, the protein amino acid levels are altered significantly. 相似文献
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This paper attempts to identify the high-risk areas for potential runoff of pyrethroid pesticides in the San Joaquin River
Watershed. Pyrethroid pesticides have been detected in water and fluvial sediments in this watershed, creating concerns about
potential negative impacts on water quality. However, little documentation exists regarding the distributions or the extent
of the adverse effects caused by the use of pyrethroids. This study developed a geographic information systems (GIS) model
to identify areas with high potential for pyrethroid runoff during the rainy season. The model was then validated using field-monitoring
data. Nine factors were identified for the runoff risk assessment: amount of active ingredient used, soil erodibility factor,
hydrologic group, surface layer depth, seasonal rainfall, seasonal number of rainy days, seasonal number of storm events,
stream density, and land cover. The results indicated that high pyrethroid runoff risks were associated with basins such as
the Stanislaus River Sub-basin, Newman Gustine Sub-basin and South Merced Sub-basin. This study demonstrated that the GIS
model is capable of predicting high-risk areas of pyrethroid runoff at sub-basin scale. The model can be used to prioritize
sites for water quality monitoring and guide implementations of best management practices.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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《Limnologica》2021
Freshwaters are particularly vulnerable to pesticide contamination from adjacent agriculture and forestry. Cypermethrin is a commonly used pyrethroid insecticide, but information on its toxicity to non-target freshwater invertebrates is limited to a small number of taxa. We assessed cypermethrin toxicity to nymphs of the common European mayflies Baetis rhodani and Ecdyonurus venosus, and the stonefly Isoperla grammatica in 96 h static bioassays. The 96 h median lethal concentrations (LC50) we recorded for the three species were 0.08 μg/L, 0.15 μg/L, and 0.13 μg/L, respectively. The effective concentration (EC50), quantified as lack of escape response (implying inability to avoid drift, predation or abiotic stress), was usually 32 % of the LC50. All 96 h LC50 values were lower than the maximum concentrations detected in streams in UK and continental Europe. Alarmingly, the 96 h LC50 for B. rhodani was below the currently applied single-pesticide EU safe drinking water standard of 0.1 μg/L. Contrasts among species were most evident at 24 h LC50, when B. rhodani was approximately ten times more sensitive than the other two taxa. B. rhodani is a key algal grazer, ubiquitous in European streams, and its decline could exacerbate algal blooms. The order of taxa sensitivity to cypermethrin in our study contrasts with their sensitivity to organic pollution in the same region, which suggests a tolerance trade-off, and thus a compounding effect of simultaneous stressors. Mayflies and stoneflies are important prey for instream and riparian predators, and key components of most eutrophication indices globally, all of which could be compromised in presence of cypermethrin. 相似文献
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Changes in the activities of two enzymes, viz., glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) following exposure to the pyrethroids fenvalerate and decis (deltamethrin), the carbamate sevin (carbaryl), singly, and the binary mixtures of fenvalerate + sevin and decis + sevin was studied in the nervous tissue of the fresh water snail Lymnaea acuminata. The total amount of the pesticides administered in the binary mixtures was very low as compared to the amount contained in the 40% LC50 and 80% LC50 of any of the pesticides when given alone. On the one hand, lower quantities of pesticides were administered, while on the other, there was greater enhancement in the activities of the two transaminases. Thus, synergism in case of transaminase activity was much more as compared to synergism when lethality was taken as a criterion. The order of effectiveness of the pesticides/mixtures was decis + sevin > fenvalerate + sevin > decis > fenvalerate > sevin. 相似文献
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