The Experts below are selected from a list of 822 Experts worldwide ranked by ideXlab platform
Inge Werner - One of the best experts on this subject based on the ideXlab platform.
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Esfenvalerate toxicity to the cladoceran ceriodaphnia dubia in the presence of green algae pseudokirchneriella subcapitata
Ecotoxicology, 2012Co-Authors: Inge Werner, Juergen Geist, Susanne M Brander, Christopher M Mosser, Michelle L HladikAbstract:The presence of phytoplankton, like other particulate organic matter, can interfere with the effects of hydrophobic contaminants such as pyrethroid pesticides. However, the reduction or elimination of toxicity by algae added as food during testing is not taken into account in standard US EPA whole effluent toxicity (WET) zooplankton tests. On the other hand, WET test conditions may overestimate toxicity of such compounds in highly productive surface waters with high concentrations of detritus and other particulate matter. In addition, WET tests do not measure impaired swimming ability or predator avoidance behavior as an indicator of increased mortality risk. This study used a modified version of the US EPA WET Ceriodaphnia dubia acute test to investigate the effects of phytoplankton on toxicity of the pyrethroid insecticide, Esfenvalerate. Animals were exposed simultaneously to different concentrations of Esfenvalerate and green algae (Pseudokirchneriella subcapitata). Mortality and predation risk were recorded after 4 and 24 h. Algae at or below concentrations specified in the WET protocol significantly reduced mortality. Regardless, organisms exposed to Esfenvalerate were unable to avoid simulated predation in the presence of algae at any concentration. After 12 h, Esfenvalerate adsorbed to algae represented 68-99 % of the total amount recovered. The proportion of algae-bound insecticide increased with algal concentration indicating that conclusions drawn from toxicity tests in which algae are added as food must be interpreted with caution as the dissolved fraction of such hydrophobic contaminants is reduced. Additionally, our results strongly suggest that the EPA should consider adding ecologically-relevant endpoints such as swimming behavior to standard WET protocols.
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BioMed Central
2009Co-Authors: Bmc Genomics, Inge Werner, Juergen Geist, Richard E Connon, Janice Pfeiff, Er V Loguinov, Ro S D&apos, Henri Wintz, Christopher D VulpeAbstract:Research article Linking mechanistic and behavioral responses to sublethal Esfenvalerate exposure in the endangered delta smelt; Hypomesus transpacificus (Fam. Osmeridae
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acute sublethal exposure to a pyrethroid insecticide alters behavior growth and predation risk in larvae of the fathead minnow pimephales promelas
Environmental Toxicology and Chemistry, 2008Co-Authors: Emily Y Floyd, Juergen Geist, Inge WernerAbstract:: The present study determined the effects of environmentally relevant, short-term (4-h) exposure to the pyrethroid insecticide Esfenvalerate on mortality, food consumption, growth, swimming ability, and predation risk in larvae of the fathead minnow (Pimephales promelas). Acute effect concentrations were determined, and in subsequent experiments, fish were exposed to the following measured sublethal concentrations: 0.072, 0.455, and 1.142 microg/L of Esfenvalerate. To measure growth rates (% dry wt/d), 8-d-old fathead minnows were exposed to Esfenvalerate for 4 h, then transferred to control water and held for 7 d. Food consumption and abnormal swimming behavior were recorded daily. Additional behavioral experiments were conducted to evaluate how Esfenvalerate affects the optomotor response of the fish. To quantify predation risk, Esfenvalerate-exposed fathead minnow larvae were transferred to 9.5-L aquaria, each containing one juvenile threespine stickleback (Gasterosteus aculeatus). Sticklebacks were allowed to feed for 45 min, after which the number of surviving minnows was recorded. No mortality occurred during 4-h exposures to Esfenvalerate, even at nominal concentrations of greater than 20 microg/L. Delayed mortality (50%) was observed at 2 microg/L after an additional 20 h in clean water. Fish exposed to 0.455 and 1.142 microg/L of Esfenvalerate exhibited impaired swimming and feeding ability as well as reduced growth compared to fish exposed to 0.072 microg/L and controls. Predation risk also was significantly increased for larvae exposed to 0.455 and 1.142 microg/L of Esfenvalerate. These results demonstrate that larval fish experiencing acute exposures to sublethal concentrations of this insecticide exhibit significant behavioral impairment, leading to reduced growth and increased susceptibility to predation, with potentially severe consequences for their ecological fitness.
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0730-7268/08 $12.00 .00 ACUTE, SUBLETHAL EXPOSURE TO A PYRETHROID INSECTICIDE ALTERS BEHAVIOR, GROWTH, AND PREDATION RISK IN LARVAE OF THE FATHEAD MINNOW (PIMEPHALES PROMELAS)
2008Co-Authors: Emily Y Floyd, Juergen P. Geist, Inge WernerAbstract:Abstract—The present study determined the effects of environmentally relevant, short-term (4-h) exposure to the pyrethroid insecticide Esfenvalerate on mortality, food consumption, growth, swimming ability, and predation risk in larvae of the fathead minnow (Pimephales promelas). Acute effect concentrations were determined, and in subsequent experiments, fish were exposed to the following measured sublethal concentrations: 0.072, 0.455, and 1.142 g/L of Esfenvalerate. To measure growth rates (% dry wt/d), 8-d-old fathead minnows were exposed to Esfenvalerate for 4 h, then transferred to control water and held for 7 d. Food consumption and abnormal swimming behavior were recorded daily. Additional behavioral experiments were conducted to evaluate how Esfenvalerate affects the optomotor response of the fish. To quantify predation risk, Esfenvalerate-exposed fathead minnow larvae were transferred to 9.5-L aquaria, each containing one juvenile threespine stickleback (Gasterosteus aculeatus). Sticklebacks were allowed to feed for 45 min, after which the number of surviving minnows was recorded. No mortality occurred during 4-h exposures to Esfenvalerate, even at nominal concentrations of greater than 20 g/L. Delayed mortality (50%) was observed at 2 g/L after an additional 20 h in clean water. Fish exposed to 0.455 and 1.142 g/L of Esfenvalerate exhibited impaired swimming and feeding ability as well as reduced growth compared to fish exposed to 0.072 g/L and controls. Predation risk also wa
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comparisons of tissue specific transcription of stress response genes with whole animal endpoints of adverse effect in striped bass morone saxatilis following treatment with copper and Esfenvalerate
Aquatic Toxicology, 2007Co-Authors: Juergen Geist, Inge Werner, Kai J Eder, Christian M LeuteneggerAbstract:Abstract Changes in the gene transcription of stress response genes in resident fish can be powerful biomarkers for the identification of sublethal impacts of environmental stressors on aquatic ecosystems. In this study, we tested the effects of two reference toxicants, copper (Cu) and the pyrethroid insecticide Esfenvalerate [( S )-α-cyano-3-phenoxybenzyl-( S )-2-(4-chlorophenyl)-3-methylbutyrate], on lethal (mortality) and sublethal endpoints (growth, swimming behavior, transcription levels of stress response genes) in juvenile (81–90-day-old) striped bass ( Morone saxatilis ). We established cellular stress response markers for proteotoxicity (HSP70, HSP90), phase I detoxification mechanism (CYP1A1), metal-binding (metallothionein), as well as immune-function and pathogen-defense (TGF-β, Mx-protein, nRAMP). Quantitative real-time TaqMan ® PCR was used to examine tissue-specific changes in the transcriptome of liver, spleen, white muscle, anterior kidney and gills after 7-day Cu exposures and 24-h Esfenvalerate exposures. On the transcriptome level, exposure to Cu showed strongest effects on the transcription of metallothionein in spleen tissue, causing a 4-fold increase of mRNA at 42 ppb total Cu and a 10-fold increase at 160 ppb Cu. Exposure to Cu also caused significant tissue-specific changes in gene transcription for immune-system related genes. Esfenvalerate exposure had tissue-specific effects on the transcription of HSP70, HSP90 and CYP1A1. The most significant effects were detected in liver tissue after exposure to 0.64 μg/L Esfenvalerate. Our results show that the stress response at the transcriptome level is a more sensitive indicator for Cu and Esfenvalerate exposures at low concentrations than swimming behavior, growth or mortality. The accuracy of studies on quantitative changes in the transcriptome can benefit from an initial evaluation or the inclusion of several different tissues and the use of multiple housekeeping genes.
Bruce D Hammock - One of the best experts on this subject based on the ideXlab platform.
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pyrethroids in house dust from the homes of farm worker families in the micasa study
Environment International, 2013Co-Authors: Kelly J Trunnelle, Deborah H Bennett, Daniel J Tancredi, Maria T Stoecklinmarois, Tamara E Hennessyburt, Bruce D Hammock, Marc B SchenkerAbstract:article Indoorpesticide exposureisa growing concern,particularlyfor pyrethroids,a commonly used class of pesticides. Pyrethroid concentrations may be especially high in homes of immigrant farm worker families, who often live in close proximity to agricultural fields and are faced with poor housing conditions, potentially causing high pest infestation and pesticide use. We investigate levels of pyrethroids in the house dust of farm worker family homes in a study of mothers and children living in Mendota, CA, within the population-based Mexican Immigra- tiontoCalifornia:AgriculturalSafetyandAcculturation(MICASA)Study.Wepresentpesticideusedataandlevels of pyrethroid pesticides in indoor dust collected in 2009 as measured by questionnaires and a GC/MS analysis of the pyrethroids cis -a ndtrans-permethrin, cypermethrin, deltamethrin, Esfenvalerate and resmethrin in single dust samples collected from 55 households. Cis -a ndtrans-permethrin had the highest detection frequencies at 67%, with median concentrations of 244 and 172 ng/g dust, respectively. Cypermethrin was detected in 52% of the homes and had a median concentration of 186 ng/g dust. Esfenvalerate, resmethrin and deltamethrin were detected in less than half the samples. We compared the pyrethroid concentrations found in our study to other studies looking at both rural and urban homes and daycares. Lower detection frequencies and/or lower median concentrations of cis -a ndtrans-permethrin and cypermethrin were observed in our study as compared to those studies. However, deltamethrin, Esfenvalerate and resmethrin were detected more frequently in the house dust from our study than in the other studies. Because households whose children had higher urinary pyrethroid metabolite levels were more likely to be analyzed in this study, a positive bias in our estimates of household pyrethroid levels may be expected. A positive association was observed with reported outdoor pesticide use and cypermethrin levels found in the indoor dust samples (rs = 0.28, p = 0.0450). There was also a positive association seen with summed pyrethroid levels inhouse dust and the results of a pesticide inventory conducted by field staff (rs =0 .32,p = 0.018), a potentially useful predictor of pesticide exposure in farm worker family homes. Further research is warranted to fully investigate the utility of such a measure.
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pyrethroids in house dust from the homes of farm worker families in the micasa study
Environment International, 2013Co-Authors: Kelly J Trunnelle, Deborah H Bennett, Daniel J Tancredi, Maria T Stoecklinmarois, Tamara E Hennessyburt, Bruce D Hammock, Shirley J Gee, Marc B SchenkerAbstract:article Indoorpesticide exposureisa growing concern,particularlyfor pyrethroids,a commonly used class of pesticides. Pyrethroid concentrations may be especially high in homes of immigrant farm worker families, who often live in close proximity to agricultural fields and are faced with poor housing conditions, potentially causing high pest infestation and pesticide use. We investigate levels of pyrethroids in the house dust of farm worker family homes in a study of mothers and children living in Mendota, CA, within the population-based Mexican Immigra- tiontoCalifornia:AgriculturalSafetyandAcculturation(MICASA)Study.Wepresentpesticideusedataandlevels of pyrethroid pesticides in indoor dust collected in 2009 as measured by questionnaires and a GC/MS analysis of the pyrethroids cis -a ndtrans-permethrin, cypermethrin, deltamethrin, Esfenvalerate and resmethrin in single dust samples collected from 55 households. Cis -a ndtrans-permethrin had the highest detection frequencies at 67%, with median concentrations of 244 and 172 ng/g dust, respectively. Cypermethrin was detected in 52% of the homes and had a median concentration of 186 ng/g dust. Esfenvalerate, resmethrin and deltamethrin were detected in less than half the samples. We compared the pyrethroid concentrations found in our study to other studies looking at both rural and urban homes and daycares. Lower detection frequencies and/or lower median concentrations of cis -a ndtrans-permethrin and cypermethrin were observed in our study as compared to those studies. However, deltamethrin, Esfenvalerate and resmethrin were detected more frequently in the house dust from our study than in the other studies. Because households whose children had higher urinary pyrethroid metabolite levels were more likely to be analyzed in this study, a positive bias in our estimates of household pyrethroid levels may be expected. A positive association was observed with reported outdoor pesticide use and cypermethrin levels found in the indoor dust samples (rs = 0.28, p = 0.0450). There was also a positive association seen with summed pyrethroid levels inhouse dust and the results of a pesticide inventory conducted by field staff (rs =0 .32,p = 0.018), a potentially useful predictor of pesticide exposure in farm worker family homes. Further research is warranted to fully investigate the utility of such a measure.
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individual variability in esterase activity and cyp1a levels in chinook salmon oncorhynchus tshawytscha exposed to Esfenvalerate and chlorpyrifos
Aquatic Toxicology, 2005Co-Authors: Craig E Wheelock, Inge Werner, Kai J Eder, Huazhang Huang, Paul D Jones, Benjamin F Brammell, Adria A Elskus, Bruce D HammockAbstract:Acetylcholinesterase (AChE) activity has traditionally been monitored as a biomarker of organophosphate (OP) and/or carbamate exposure. However, AChE activity may not be the most sensitive endpoint for these agrochemicals, because OPs can cause adverse physiological effects at concentrations that do not affect AChE activity. Carboxylesterases are a related family of enzymes that have higher affinity than AChE for some OPs and carbamates and may be more sensitive indicators of environmental exposure to these pesticides. In this study, carboxylesterase and AChE activity, cytochrome P4501A (CYP1A) protein levels, and mortality were measured in individual juvenile Chinook salmon (Oncorhynchus tshawytscha) following exposure to an OP (chlorpyrifos) and a pyrethroid (Esfenvalerate). As expected, high doses of chlorpyrifos and Esfenvalerate were acutely toxic, with nominal concentrations (100 and 1 μg/l, respectively) causing 100% mortality within 96 h. Exposure to chlorpyrifos at a high dose (7.3 μg/l), but not a low dose (1.2 μg/l), significantly inhibited AChE activity in both brain and muscle tissue (85% and 92% inhibition, respectively), while Esfenvalerate exposure had no effect. In contrast, liver carboxylesterase activity was significantly inhibited at both the low and high chlorpyrifos dose exposure (56% and 79% inhibition, respectively), while Esfenvalerate exposure still had little effect. The inhibition of carboxylesterase activity at levels of chlorpyrifos that did not affect AChE activity suggests that some salmon carboxylesterase isozymes may be more sensitive than AChE to inhibition by OPs. CYP1A protein levels were ∼30% suppressed by chlorpyrifos exposure at the high dose, but Esfenvalerate had no effect. Three teleost species, Chinook salmon, medaka (Oryzias latipes) and Sacramento splittail (Pogonichthys macrolepidotus), were examined for their ability to hydrolyze a series of pyrethroid surrogate substrates and in all cases hydrolysis activity was undetectable. Together these data suggest that (1) carboxylesterase activity inhibition may be a more sensitive biomarker for OP exposure than AChE activity, (2) neither AChE nor carboxylesterase activity are biomarkers for pyrethroid exposure, (3) CYP1A protein is not a sensitive marker for these agrochemicals and (4) slow hydrolysis rates may be partly responsible for acute pyrethroid toxicity in fish.
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joint acute toxicity of Esfenvalerate and diazinon to larval fathead minnows pimephales promelas
Environmental Toxicology and Chemistry, 2003Co-Authors: Debra L Denton, Bruce D Hammock, Craig E Wheelock, Shauna A Murray, Linda A Deanovic, David E HintonAbstract:California (USA) agriculture employs pyrethroid and organophosphate insecticides to control insects in orchards and other crops. Diazinon and Esfenvalerate were selected for this study because of their application overlaps. Toxicological and biochemical responses of larval fathead minnows (Pimephales promelas) exposed singly and in combinations to Esfenvalerate and diazinon were determined. Exposures were 96-h static renewal tests that used standard U.S. Environmental Protection Agency acute toxicity test methods. After pesticide exposures, larvae were evaluated for carboxylesterase and acetylcholinesterase activity, and histopathological effects. Carboxylesterase activity was examined because of its potential influence on the toxicity of both organophosphates and pyrethroids. In vivo studies demonstrated that diazinon significantly inhibited carboxylesterase activity at nominal water concentrations as low as 50 μg/L. However, Esfenvalerate did not affect carboxylesterase activity at any concentration tested. Liver glycogen depletion was the only histopathological effect observed; this effect was demonstrated with the individual pesticides and pesticide combinations (i.e., mixtures). The combinations of diazinon and Esfenvalerate causing acute toxicity to fathead minnow larvae appeared to be greater than additive (i.e., synergistic) in all three tests.
Emily Y Floyd - One of the best experts on this subject based on the ideXlab platform.
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acute sublethal exposure to a pyrethroid insecticide alters behavior growth and predation risk in larvae of the fathead minnow pimephales promelas
Environmental Toxicology and Chemistry, 2008Co-Authors: Emily Y Floyd, Juergen Geist, Inge WernerAbstract:: The present study determined the effects of environmentally relevant, short-term (4-h) exposure to the pyrethroid insecticide Esfenvalerate on mortality, food consumption, growth, swimming ability, and predation risk in larvae of the fathead minnow (Pimephales promelas). Acute effect concentrations were determined, and in subsequent experiments, fish were exposed to the following measured sublethal concentrations: 0.072, 0.455, and 1.142 microg/L of Esfenvalerate. To measure growth rates (% dry wt/d), 8-d-old fathead minnows were exposed to Esfenvalerate for 4 h, then transferred to control water and held for 7 d. Food consumption and abnormal swimming behavior were recorded daily. Additional behavioral experiments were conducted to evaluate how Esfenvalerate affects the optomotor response of the fish. To quantify predation risk, Esfenvalerate-exposed fathead minnow larvae were transferred to 9.5-L aquaria, each containing one juvenile threespine stickleback (Gasterosteus aculeatus). Sticklebacks were allowed to feed for 45 min, after which the number of surviving minnows was recorded. No mortality occurred during 4-h exposures to Esfenvalerate, even at nominal concentrations of greater than 20 microg/L. Delayed mortality (50%) was observed at 2 microg/L after an additional 20 h in clean water. Fish exposed to 0.455 and 1.142 microg/L of Esfenvalerate exhibited impaired swimming and feeding ability as well as reduced growth compared to fish exposed to 0.072 microg/L and controls. Predation risk also was significantly increased for larvae exposed to 0.455 and 1.142 microg/L of Esfenvalerate. These results demonstrate that larval fish experiencing acute exposures to sublethal concentrations of this insecticide exhibit significant behavioral impairment, leading to reduced growth and increased susceptibility to predation, with potentially severe consequences for their ecological fitness.
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0730-7268/08 $12.00 .00 ACUTE, SUBLETHAL EXPOSURE TO A PYRETHROID INSECTICIDE ALTERS BEHAVIOR, GROWTH, AND PREDATION RISK IN LARVAE OF THE FATHEAD MINNOW (PIMEPHALES PROMELAS)
2008Co-Authors: Emily Y Floyd, Juergen P. Geist, Inge WernerAbstract:Abstract—The present study determined the effects of environmentally relevant, short-term (4-h) exposure to the pyrethroid insecticide Esfenvalerate on mortality, food consumption, growth, swimming ability, and predation risk in larvae of the fathead minnow (Pimephales promelas). Acute effect concentrations were determined, and in subsequent experiments, fish were exposed to the following measured sublethal concentrations: 0.072, 0.455, and 1.142 g/L of Esfenvalerate. To measure growth rates (% dry wt/d), 8-d-old fathead minnows were exposed to Esfenvalerate for 4 h, then transferred to control water and held for 7 d. Food consumption and abnormal swimming behavior were recorded daily. Additional behavioral experiments were conducted to evaluate how Esfenvalerate affects the optomotor response of the fish. To quantify predation risk, Esfenvalerate-exposed fathead minnow larvae were transferred to 9.5-L aquaria, each containing one juvenile threespine stickleback (Gasterosteus aculeatus). Sticklebacks were allowed to feed for 45 min, after which the number of surviving minnows was recorded. No mortality occurred during 4-h exposures to Esfenvalerate, even at nominal concentrations of greater than 20 g/L. Delayed mortality (50%) was observed at 2 g/L after an additional 20 h in clean water. Fish exposed to 0.455 and 1.142 g/L of Esfenvalerate exhibited impaired swimming and feeding ability as well as reduced growth compared to fish exposed to 0.072 g/L and controls. Predation risk also wa
Juergen Geist - One of the best experts on this subject based on the ideXlab platform.
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Esfenvalerate toxicity to the cladoceran ceriodaphnia dubia in the presence of green algae pseudokirchneriella subcapitata
Ecotoxicology, 2012Co-Authors: Inge Werner, Juergen Geist, Susanne M Brander, Christopher M Mosser, Michelle L HladikAbstract:The presence of phytoplankton, like other particulate organic matter, can interfere with the effects of hydrophobic contaminants such as pyrethroid pesticides. However, the reduction or elimination of toxicity by algae added as food during testing is not taken into account in standard US EPA whole effluent toxicity (WET) zooplankton tests. On the other hand, WET test conditions may overestimate toxicity of such compounds in highly productive surface waters with high concentrations of detritus and other particulate matter. In addition, WET tests do not measure impaired swimming ability or predator avoidance behavior as an indicator of increased mortality risk. This study used a modified version of the US EPA WET Ceriodaphnia dubia acute test to investigate the effects of phytoplankton on toxicity of the pyrethroid insecticide, Esfenvalerate. Animals were exposed simultaneously to different concentrations of Esfenvalerate and green algae (Pseudokirchneriella subcapitata). Mortality and predation risk were recorded after 4 and 24 h. Algae at or below concentrations specified in the WET protocol significantly reduced mortality. Regardless, organisms exposed to Esfenvalerate were unable to avoid simulated predation in the presence of algae at any concentration. After 12 h, Esfenvalerate adsorbed to algae represented 68-99 % of the total amount recovered. The proportion of algae-bound insecticide increased with algal concentration indicating that conclusions drawn from toxicity tests in which algae are added as food must be interpreted with caution as the dissolved fraction of such hydrophobic contaminants is reduced. Additionally, our results strongly suggest that the EPA should consider adding ecologically-relevant endpoints such as swimming behavior to standard WET protocols.
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BioMed Central
2009Co-Authors: Bmc Genomics, Inge Werner, Juergen Geist, Richard E Connon, Janice Pfeiff, Er V Loguinov, Ro S D&apos, Henri Wintz, Christopher D VulpeAbstract:Research article Linking mechanistic and behavioral responses to sublethal Esfenvalerate exposure in the endangered delta smelt; Hypomesus transpacificus (Fam. Osmeridae
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acute sublethal exposure to a pyrethroid insecticide alters behavior growth and predation risk in larvae of the fathead minnow pimephales promelas
Environmental Toxicology and Chemistry, 2008Co-Authors: Emily Y Floyd, Juergen Geist, Inge WernerAbstract:: The present study determined the effects of environmentally relevant, short-term (4-h) exposure to the pyrethroid insecticide Esfenvalerate on mortality, food consumption, growth, swimming ability, and predation risk in larvae of the fathead minnow (Pimephales promelas). Acute effect concentrations were determined, and in subsequent experiments, fish were exposed to the following measured sublethal concentrations: 0.072, 0.455, and 1.142 microg/L of Esfenvalerate. To measure growth rates (% dry wt/d), 8-d-old fathead minnows were exposed to Esfenvalerate for 4 h, then transferred to control water and held for 7 d. Food consumption and abnormal swimming behavior were recorded daily. Additional behavioral experiments were conducted to evaluate how Esfenvalerate affects the optomotor response of the fish. To quantify predation risk, Esfenvalerate-exposed fathead minnow larvae were transferred to 9.5-L aquaria, each containing one juvenile threespine stickleback (Gasterosteus aculeatus). Sticklebacks were allowed to feed for 45 min, after which the number of surviving minnows was recorded. No mortality occurred during 4-h exposures to Esfenvalerate, even at nominal concentrations of greater than 20 microg/L. Delayed mortality (50%) was observed at 2 microg/L after an additional 20 h in clean water. Fish exposed to 0.455 and 1.142 microg/L of Esfenvalerate exhibited impaired swimming and feeding ability as well as reduced growth compared to fish exposed to 0.072 microg/L and controls. Predation risk also was significantly increased for larvae exposed to 0.455 and 1.142 microg/L of Esfenvalerate. These results demonstrate that larval fish experiencing acute exposures to sublethal concentrations of this insecticide exhibit significant behavioral impairment, leading to reduced growth and increased susceptibility to predation, with potentially severe consequences for their ecological fitness.
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comparisons of tissue specific transcription of stress response genes with whole animal endpoints of adverse effect in striped bass morone saxatilis following treatment with copper and Esfenvalerate
Aquatic Toxicology, 2007Co-Authors: Juergen Geist, Inge Werner, Kai J Eder, Christian M LeuteneggerAbstract:Abstract Changes in the gene transcription of stress response genes in resident fish can be powerful biomarkers for the identification of sublethal impacts of environmental stressors on aquatic ecosystems. In this study, we tested the effects of two reference toxicants, copper (Cu) and the pyrethroid insecticide Esfenvalerate [( S )-α-cyano-3-phenoxybenzyl-( S )-2-(4-chlorophenyl)-3-methylbutyrate], on lethal (mortality) and sublethal endpoints (growth, swimming behavior, transcription levels of stress response genes) in juvenile (81–90-day-old) striped bass ( Morone saxatilis ). We established cellular stress response markers for proteotoxicity (HSP70, HSP90), phase I detoxification mechanism (CYP1A1), metal-binding (metallothionein), as well as immune-function and pathogen-defense (TGF-β, Mx-protein, nRAMP). Quantitative real-time TaqMan ® PCR was used to examine tissue-specific changes in the transcriptome of liver, spleen, white muscle, anterior kidney and gills after 7-day Cu exposures and 24-h Esfenvalerate exposures. On the transcriptome level, exposure to Cu showed strongest effects on the transcription of metallothionein in spleen tissue, causing a 4-fold increase of mRNA at 42 ppb total Cu and a 10-fold increase at 160 ppb Cu. Exposure to Cu also caused significant tissue-specific changes in gene transcription for immune-system related genes. Esfenvalerate exposure had tissue-specific effects on the transcription of HSP70, HSP90 and CYP1A1. The most significant effects were detected in liver tissue after exposure to 0.64 μg/L Esfenvalerate. Our results show that the stress response at the transcriptome level is a more sensitive indicator for Cu and Esfenvalerate exposures at low concentrations than swimming behavior, growth or mortality. The accuracy of studies on quantitative changes in the transcriptome can benefit from an initial evaluation or the inclusion of several different tissues and the use of multiple housekeeping genes.
Ronald S. Tjeerdema - One of the best experts on this subject based on the ideXlab platform.
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Metabolic effects of dinoseb, diazinon and Esfenvalerate in eyed eggs and alevins of Chinook salmon (Oncorhynchus tshawytscha) determined by 1H NMR metabolomics
Aquatic Toxicology, 2006Co-Authors: Mark R. Viant, Christopher A. Pincetich, Ronald S. TjeerdemaAbstract:Pesticide pulses in the Sacramento River, California, originate from storm-water discharges and non-point source aquatic pollution that can last from a few days to weeks. The Sacramento River and its tributaries have historically supported the majority of California’s Chinook salmon (Oncorhynchus tshawytscha) spawning grounds. Three pesticides currently used in the Sacramento Valley – dinoseb, diazinon, and Esfenvalerate – were chosen to model the exposure of salmon embryos to storm-water discharges. Static-renewal (96 h) exposures to eyed eggs and alevins resulted in both toxicity and significant changes in metabolism assessed in whole-embryo extracts by 1 H nuclear magnetic resonance (NMR) spectroscopy based metabolomics and HPLC with UV detection (HPLC-UV). The 96-h LC50 values of eyed eggs and alevins exposed to dinoseb were 335 and 70.6 ppb, respectively, and the corresponding values for diazinon were 545 and 29.5 ppm for eyed eggs and alevins, respectively. The 96-h LC50 of eyed eggs exposed to Esfenvalerate could not be determined due to lack of mortality at the highest exposure concentration, but in alevins was 16.7 ppb. All Esfenvalerate exposed alevins developed some degree of lordosis or myoskeletal abnormality and did not respond to stimulus or exhibit normal swimming behavior. ATP concentrations measured by HPLC-UV decreased significantly in eyed eggs due to 250 ppb dinoseb and 10 and 100 ppb Esfenvalerate (p < 0.05). Phosphocreatine, as measured by HPLC-UV, decreased significantly in eyed eggs due to 250 ppb dinoseb, 10 and 100 ppb Esfenvalerate, and 100 ppm diazinon (p < 0.05). Principal components analyses of 1 H NMR metabolite fingerprints of eyed egg and alevin extracts revealed both dose-dependent and mechanism of action-specific metabolic effects induced by the pesticides. Furthermore, NMR based metabolomics proved to be more sensitive than HPLC-UV in identifying significant changes in sublethal metabolism of pesticide exposed alevins. In conclusion, we have demonstrated several benefits of a metabolomics approach for chemical risk assessment, when used in conjunction with a fish embryo assay, and have identified significant metabolic perturbations to the early life stages of Chinook salmon by currently used pesticides.
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chemistry and fate of fenvalerate and Esfenvalerate
Reviews of Environmental Contamination and Toxicology, 2003Co-Authors: Terrence L Adelsbach, Ronald S. TjeerdemaAbstract:Widespread use of synthetic insecticides began in the United States following World War II. Previously, natural compounds such as arsenic, nicotine, pyrethrum, rotenone, and others were used for pest control. These agents lacked many of the key advantages of their manufactured successors, such as efficacy, spectrum, specificity, environmental stability, and applicator safety. During the past five decades, agriculture in the U.S. has dispersed some 30 billion pounds of pesticides into the environment. In the U.S., some 1.23 billion pounds of active ingredient currently are released annually; approximately 944 million pounds are used in agriculture, with the remainder for other purposes such as industrial and government programs and household pest control (USEPA 1999). Consequently, agricultural production in much of the world has dramatically increased, and insect-borne diseases such as malaria have been effectively controlled. However, one of the unforeseen consequences of widespread insecticide use has been the rise in insect resistance over the past 50 years. New research into the secondary effects of insecticides has also uncovered other unforeseen consequences such as endocrine disruption and carcinogenicity.