The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Amanda Callaghan - One of the best experts on this subject based on the ideXlab platform.
-
induction of cytochrome p 450 activity in individual Chironomus Riparius meigen larvae exposed to xenobiotics
Ecotoxicology and Environmental Safety, 2003Co-Authors: Thomas C Fisher, Mark Crane, Amanda CallaghanAbstract:Cytochrome P450 activity in individual Chironomus Riparius larvae was measured using a microtiter plate adaptation of the ethoxyresorufin-O-deethylase (EROD) assay. The sensitivity of this biomarker was tested by exposing larvae to phenobarbital (0.5 and 1.0 mM) and permethrin (1 and 10 μg/g). Both chemicals induced EROD activity in C. Riparius larvae by up to 1.58-fold with PB and 2.47-fold with permethrin. EROD induction was more pronounced after 48 h. The initially high EROD activity in the controls suggested that P450s are induced by stress. Feeding levels prior to exposure also had a significant effect on EROD activity. EROD activity compared to the control was highest when larvae were fed double the normal ration. These results indicate that EROD activity in individual C. Riparius may be a useful biomarker to add to a suite of biomarkers for the detection of freshwater pollution.
-
relationship between biomarker activity and developmental endpoints in Chironomus Riparius meigen exposed to an organophosphate insecticide
Ecotoxicology and Environmental Safety, 2002Co-Authors: Mark Crane, Wanwisu Sildanchandra, R Kheir, Amanda CallaghanAbstract:The biomarkers acetylcholinesterase (AChE) and glutathione S-transferase (GST) were measured in fourth-instar Chironomus Riparius Meigen larvae exposed to the organophosphate insecticide pirimiphos methyl (0, 5, 10, and 50 ng/g) for 48 or 96 h, and at high or low food ration. Larvae exposed to 50 ng/g pirimiphos methyl died within 48 h. The weight of larvae exposed to 10 ng/g pirimiphos methyl was significantly lower than those exposed to 0 and 5 ng/g. AChE activity was significantly reduced in larvae exposed to 10 ng/g, but GST activity remained unaffected. Lower food ration reduced larval weights across all treatments but did not affect biomarker measurements. Insecticide exposure was associated with a longer time to adult emergence and oviposition, fewer egg masses, a greater proportion of deformed egg masses, and fewer eggs.
-
effect of temperature and pirimiphos methyl on biochemical biomarkers in Chironomus Riparius meigen
Ecotoxicology and Environmental Safety, 2002Co-Authors: Amanda Callaghan, Thomas C Fisher, Albania Grosso, Graham J Holloway, Mark CraneAbstract:Abstract Fourth-instar Chironomus Riparius Meigen larvae were exposed to the organophosphate (OP) insecticide pirimiphos methyl (0, 0.1, 1.0, and 10 μg/L) for 48, 72, or 96 h at three temperatures (3, 12, or 22°C). Two biochemical biomarkers, acetylcholinesterase (AChE) and glutathione S-transferase (GST), were measured in individual larvae from each treatment. AChE activity was inhibited by the OP in a dose-responsive fashion. This response remained similar at all three temperatures, demonstrating that AChE is a robust and specific biomarker. Exposure duration had little effect on AChE activity. In contrast, GST activity was induced at the highest OP insecticide concentration, but induction was also evident at 3°C. There was a significant effect of exposure duration, with an overall decline in GST activity over time. This result agrees with previous work suggesting that GSTs are not particularly suitable for use as a biomarker of pesticide exposure or effect in Chironomus.
-
Effect of Short-Term Exposure to Chlorpyrifos on Developmental Parameters and Biochemical Biomarkers in Chironomus Riparius Meigen
Ecotoxicology and Environmental Safety, 2001Co-Authors: Amanda Callaghan, G. Hirthe, T. Fisher, Mark CraneAbstract:Chironomus Riparius Meigen were exposed to sediment spiked with 0, 0.01, 0.05, and 0.10 mg chlorpyrifos/kg dry sediment for 48 h as late third-instar larvae. Acetylcholinesterase activity, glutathione-S-transferase activity, burrowing behavior, emergence time, and adult dry weight were measured to determine which were the most sensitive biomarkers of exposure and effect for short-term sublethal exposures. There was a significant drop in acetylcholinesterase activity at the two highest concentrations, but no effect on glutathione-S-transferase activity. Behavioral and life history biomarkers were sensitive only to the highest concentration of chlorpyrifos. The association of life history changes (female weight and male emergence times) with a significant inhibition of acetylcholinesterase activity suggests that this can be used as a biomarker of exposure and effect.
-
variability in acetylcholinesterase and glutathione s transferase activities in Chironomus Riparius meigen deployed in situ at uncontaminated field sites
Environmental Toxicology and Chemistry, 2001Co-Authors: Tony Olsen, Amanda Callaghan, Lucy Ellerbeck, Tom Fisher, Mark CraneAbstract:An in situ system was used to expose fourth instar Chironomus Riparius Meigen larvae for 48-h at 13 uncontaminated river sites across southeast England. Acetylcholinesterase (AChE) and glutathione S-transferase (GST) activities were measured in individual larvae recovered from these sites. Activities of both biomarkers varied almost twofold across the sites, with statistically significant differences detectable between sites. There were no clear relationships between biomarker activities and physical or chemical characteristics measured at each site. This study shows that biomarker measurements can be used successfully in conjunction with an in situ system. However, the results of statistically significant biomarker results must be treated with caution because natural variability in responses can occur even in the absence of toxicant exposure.
Amadeu M.v.m. Soares - One of the best experts on this subject based on the ideXlab platform.
-
amitraz toxicity to the midge Chironomus Riparius life history and biochemical responses
Chemosphere, 2019Co-Authors: Amadeu M.v.m. Soares, Hugo R Monteiro, Marco F L Lemos, Sara C Novais, Joao L T PestanaAbstract:Abstract Acute and chronic toxicity of the formamidine pesticide amitraz to the midge Chironomus Riparius was assessed using conventional ecotoxicological tests and biochemical approaches (biomarkers). Amitraz is mainly used as an ectoparasiticide in veterinary medicine, but also in agriculture and apiculture. However, information of amitraz toxicity to non-target invertebrates is limited. Besides the impairment of developmental and emergence rates (reduced larval growth, emergence, and delayed development time) caused by chronic exposure to amitraz, acute exposures induced alterations in the antioxidant enzymes glutathione peroxidase (GPx) and catalase (CAT), and in energetic metabolism biomarkers, lactate dehydrogenase (LDH) and electron transport system (ETS) activities. Moreover, lipid peroxidation (LPO) increased by amitraz exposure. Our results reveal potential secondary effects of amitraz to invertebrates and biomarkers that may aid in the interpretation of sub-lethal toxic responses to amitraz. These results add information concerning the potential outcomes of amitraz exposure to freshwater invertebrates underlining the importance of risk assessment studies of formamidine pesticides.
-
toxicity of organic uv filters to the aquatic midge Chironomus Riparius
Ecotoxicology and Environmental Safety, 2017Co-Authors: Diana Campos, Amadeu M.v.m. Soares, Vladimir žlabek, Carlos Gravato, Carla Quintaneiro, Oksana Golovko, Joao L T PestanaAbstract:Abstract Despite the frequent detection of organic ultraviolet-filters (UV-filters) in freshwater sediments, there is a lack of ecotoxicological data undermining a correct risk assessment for these emerging contaminants. The present study assessed the effects of three of the most commonly used UV-filters (benzophenone-3 – BP3; 3-(4-methylbenzylidene)camphor – 4-MBC and octocrylene – OC) on Chironomus Riparius life history and biochemical responses. Standard ecotoxicological assays confirmed that all compounds impaired growth of C. Riparius larvae and induced developmental effects such as delayed emergence and a reduction of imagoes weight. Concerning the biochemical responses analysed no evidences of oxidative damage in lipids or neurotoxicity (tested assessing acetylcholinesterase activity) were observed for any of the tested compounds. However, 4-MBC exposure induced a decrease in catalase activity and an increase in glutathione-S-transferase activity at 14.13 mg/Kg while OC exposure caused an increase in total glutathione levels at 0.23 and 18.23 mg/Kg. Exposure to all UV-filters tested, increased energy consumption on C. Riparius with significant differences above 1.00 mg/Kg for BP3, 0.09 mg/Kg for 4-MBC and 2.13 mg/Kg for OC. These results suggest that environmental relevant concentrations of UV-filters can cause deleterious effects to aquatic benthic species, such as C. Riparius, and call for further research concerning effects of organic UV-filters on natural invertebrate communities and ecosystem functioning.
-
responses of the aquatic midge Chironomus Riparius to deet exposure
Aquatic Toxicology, 2016Co-Authors: Diana Campos, Amadeu M.v.m. Soares, Carlos Gravato, Carla Quintaneiro, Joao L T PestanaAbstract:Abstract N,N-diethyl-3-methylbenzamide (DEET) is the active ingredient of many commercial insect repellents. Despite being detected worldwide in effluents, surface water and groundwater, there is still limited information on DEET’s toxicity toward non-target aquatic invertebrates. Thus, our main objective was to assess the effects of DEET in the life cycle of Chironomus Riparius and assess its biochemical effects. Laboratory assays showed that DEET reduced developmental rates (reduced larval growth, delayed emergence) of C. Riparius larvae and also caused a decrease in the size of adult midges. Concerning the biochemical responses, a short exposure to DEET caused no effects in lipid peroxidation, despite the significant inhibition of catalase and glutathione-S-transferase activities and of total glutathione contents. Moreover, inhibition of acetylcholinesterase activity was also observed showing neurotoxic effects. Environmental risk assessment of insect repellents is needed. Our results showed moderate toxicity of DEET toward C. Riparius, however, due to their mode of action, indirect ecological effects of DEET and of other insect repellents cannot be excluded and should be evaluated.
-
sub lethal toxicity of environmentally relevant concentrations of esfenvalerate to Chironomus Riparius
Environmental Pollution, 2015Co-Authors: Amadeu M.v.m. Soares, Andreia C M Rodrigues, Carlos Gravato, Carla Quintaneiro, Carlos Barata, Joao L T PestanaAbstract:Integrative studies focused on sub-organismal responses to pyrethroid exposure are important to understand life history responses. In this study, the ecotoxicological effects of esfenvalerate (ESF) on Chironomus Riparius were assessed using five biochemical biomarkers related to neurophysiological function (acetylcholinesterase) and oxidative stress (catalase; glutathione-S-transferase; total glutathione and lipid peroxidation). In addition, effects on cellular energy allocation were assessed and all results were compared with organismal level responses (larval growth, emergence and sex ratio). Exposure to sub-lethal concentrations of ESF caused the failure of C. Riparius antioxidant defenses (inhibition of catalase activity and decreased levels of total glutathione), which was reflected as oxidative damage. C. Riparius energy budget was decreased by exposure to ESF due to an increased energy consumption. Life cycle tests showed that exposure to ESF impaired C. Riparius developmental rates and increased male:female ratios, thereby confirming its toxicity and potential population level effects at environmentally relevant concentrations.
-
effects of imidacloprid exposure on Chironomus Riparius meigen larvae linking acetylcholinesterase activity to behaviour
Ecotoxicology and Environmental Safety, 2011Co-Authors: Henrique M V S Azevedopereira, Marco F L Lemos, Amadeu M.v.m. SoaresAbstract:Abstract Imidacloprid (IMI) is an insecticide that interferes with the transmission of stimuli in the nervous system of insects. It is neurotoxic by mimicking nicotine through its binding to the nicotinic acetylcholine receptor. In this work, experiments comprising 96 h exposure followed by 48 h in clean medium were conducted to evaluate the toxicity of IMI to Chironomus Riparius and its potential recovery. Behavioural parameters and AChE activity were assessed. After 96 h exposure to IMI, AChE activity, and the behaviour parameters ventilation and locomotion were reduced. There were no signs of recovery after removal to clean water for 48 h. Ventilation behaviour was the most sensitive parameter and the one with the highest correlation to AChE activity. Despite the possibility that IMI might be having an indirect effect on AChE activity, the behavioural endpoint showed a higher sensitivity than the biochemical response itself. This work highlights the importance of linking parameters with ecological relevance at individual level (behavioural parameters) with biochemical responses, to unravel xenobiotics mode of action.
Thomas C Fisher - One of the best experts on this subject based on the ideXlab platform.
-
induction of cytochrome p 450 activity in individual Chironomus Riparius meigen larvae exposed to xenobiotics
Ecotoxicology and Environmental Safety, 2003Co-Authors: Thomas C Fisher, Mark Crane, Amanda CallaghanAbstract:Cytochrome P450 activity in individual Chironomus Riparius larvae was measured using a microtiter plate adaptation of the ethoxyresorufin-O-deethylase (EROD) assay. The sensitivity of this biomarker was tested by exposing larvae to phenobarbital (0.5 and 1.0 mM) and permethrin (1 and 10 μg/g). Both chemicals induced EROD activity in C. Riparius larvae by up to 1.58-fold with PB and 2.47-fold with permethrin. EROD induction was more pronounced after 48 h. The initially high EROD activity in the controls suggested that P450s are induced by stress. Feeding levels prior to exposure also had a significant effect on EROD activity. EROD activity compared to the control was highest when larvae were fed double the normal ration. These results indicate that EROD activity in individual C. Riparius may be a useful biomarker to add to a suite of biomarkers for the detection of freshwater pollution.
-
effect of temperature and pirimiphos methyl on biochemical biomarkers in Chironomus Riparius meigen
Ecotoxicology and Environmental Safety, 2002Co-Authors: Amanda Callaghan, Thomas C Fisher, Albania Grosso, Graham J Holloway, Mark CraneAbstract:Abstract Fourth-instar Chironomus Riparius Meigen larvae were exposed to the organophosphate (OP) insecticide pirimiphos methyl (0, 0.1, 1.0, and 10 μg/L) for 48, 72, or 96 h at three temperatures (3, 12, or 22°C). Two biochemical biomarkers, acetylcholinesterase (AChE) and glutathione S-transferase (GST), were measured in individual larvae from each treatment. AChE activity was inhibited by the OP in a dose-responsive fashion. This response remained similar at all three temperatures, demonstrating that AChE is a robust and specific biomarker. Exposure duration had little effect on AChE activity. In contrast, GST activity was induced at the highest OP insecticide concentration, but induction was also evident at 3°C. There was a significant effect of exposure duration, with an overall decline in GST activity over time. This result agrees with previous work suggesting that GSTs are not particularly suitable for use as a biomarker of pesticide exposure or effect in Chironomus.
-
an optimized microtiterplate assay to detect acetylcholinesterase activity in individual Chironomus Riparius meigen
Environmental Toxicology and Chemistry, 2000Co-Authors: Thomas C Fisher, Mark Crane, Amanda CallaghanAbstract:A sensitive microtiter plate assay to detect acetylcholinesterase activity in fourth-instar Chironomus Riparius (Meigen) larvae was developed and optimized to allow the measurement of pesticide inhibition in individuals. Optimal conditions, including enzyme concentration, pH, and substrate concentration, allow the sensitive measurement of changes in activity following exposure to the organophosphate insecticide chlorpyrifos. Significant reductions in activity were observed at pesticide doses of 0.05, 0.1, 1.0, and 5 mg/L following a 48-h exposure.
Mark Crane - One of the best experts on this subject based on the ideXlab platform.
-
induction of cytochrome p 450 activity in individual Chironomus Riparius meigen larvae exposed to xenobiotics
Ecotoxicology and Environmental Safety, 2003Co-Authors: Thomas C Fisher, Mark Crane, Amanda CallaghanAbstract:Cytochrome P450 activity in individual Chironomus Riparius larvae was measured using a microtiter plate adaptation of the ethoxyresorufin-O-deethylase (EROD) assay. The sensitivity of this biomarker was tested by exposing larvae to phenobarbital (0.5 and 1.0 mM) and permethrin (1 and 10 μg/g). Both chemicals induced EROD activity in C. Riparius larvae by up to 1.58-fold with PB and 2.47-fold with permethrin. EROD induction was more pronounced after 48 h. The initially high EROD activity in the controls suggested that P450s are induced by stress. Feeding levels prior to exposure also had a significant effect on EROD activity. EROD activity compared to the control was highest when larvae were fed double the normal ration. These results indicate that EROD activity in individual C. Riparius may be a useful biomarker to add to a suite of biomarkers for the detection of freshwater pollution.
-
relationship between biomarker activity and developmental endpoints in Chironomus Riparius meigen exposed to an organophosphate insecticide
Ecotoxicology and Environmental Safety, 2002Co-Authors: Mark Crane, Wanwisu Sildanchandra, R Kheir, Amanda CallaghanAbstract:The biomarkers acetylcholinesterase (AChE) and glutathione S-transferase (GST) were measured in fourth-instar Chironomus Riparius Meigen larvae exposed to the organophosphate insecticide pirimiphos methyl (0, 5, 10, and 50 ng/g) for 48 or 96 h, and at high or low food ration. Larvae exposed to 50 ng/g pirimiphos methyl died within 48 h. The weight of larvae exposed to 10 ng/g pirimiphos methyl was significantly lower than those exposed to 0 and 5 ng/g. AChE activity was significantly reduced in larvae exposed to 10 ng/g, but GST activity remained unaffected. Lower food ration reduced larval weights across all treatments but did not affect biomarker measurements. Insecticide exposure was associated with a longer time to adult emergence and oviposition, fewer egg masses, a greater proportion of deformed egg masses, and fewer eggs.
-
effect of temperature and pirimiphos methyl on biochemical biomarkers in Chironomus Riparius meigen
Ecotoxicology and Environmental Safety, 2002Co-Authors: Amanda Callaghan, Thomas C Fisher, Albania Grosso, Graham J Holloway, Mark CraneAbstract:Abstract Fourth-instar Chironomus Riparius Meigen larvae were exposed to the organophosphate (OP) insecticide pirimiphos methyl (0, 0.1, 1.0, and 10 μg/L) for 48, 72, or 96 h at three temperatures (3, 12, or 22°C). Two biochemical biomarkers, acetylcholinesterase (AChE) and glutathione S-transferase (GST), were measured in individual larvae from each treatment. AChE activity was inhibited by the OP in a dose-responsive fashion. This response remained similar at all three temperatures, demonstrating that AChE is a robust and specific biomarker. Exposure duration had little effect on AChE activity. In contrast, GST activity was induced at the highest OP insecticide concentration, but induction was also evident at 3°C. There was a significant effect of exposure duration, with an overall decline in GST activity over time. This result agrees with previous work suggesting that GSTs are not particularly suitable for use as a biomarker of pesticide exposure or effect in Chironomus.
-
Effect of Short-Term Exposure to Chlorpyrifos on Developmental Parameters and Biochemical Biomarkers in Chironomus Riparius Meigen
Ecotoxicology and Environmental Safety, 2001Co-Authors: Amanda Callaghan, G. Hirthe, T. Fisher, Mark CraneAbstract:Chironomus Riparius Meigen were exposed to sediment spiked with 0, 0.01, 0.05, and 0.10 mg chlorpyrifos/kg dry sediment for 48 h as late third-instar larvae. Acetylcholinesterase activity, glutathione-S-transferase activity, burrowing behavior, emergence time, and adult dry weight were measured to determine which were the most sensitive biomarkers of exposure and effect for short-term sublethal exposures. There was a significant drop in acetylcholinesterase activity at the two highest concentrations, but no effect on glutathione-S-transferase activity. Behavioral and life history biomarkers were sensitive only to the highest concentration of chlorpyrifos. The association of life history changes (female weight and male emergence times) with a significant inhibition of acetylcholinesterase activity suggests that this can be used as a biomarker of exposure and effect.
-
variability in acetylcholinesterase and glutathione s transferase activities in Chironomus Riparius meigen deployed in situ at uncontaminated field sites
Environmental Toxicology and Chemistry, 2001Co-Authors: Tony Olsen, Amanda Callaghan, Lucy Ellerbeck, Tom Fisher, Mark CraneAbstract:An in situ system was used to expose fourth instar Chironomus Riparius Meigen larvae for 48-h at 13 uncontaminated river sites across southeast England. Acetylcholinesterase (AChE) and glutathione S-transferase (GST) activities were measured in individual larvae recovered from these sites. Activities of both biomarkers varied almost twofold across the sites, with statistically significant differences detectable between sites. There were no clear relationships between biomarker activities and physical or chemical characteristics measured at each site. This study shows that biomarker measurements can be used successfully in conjunction with an in situ system. However, the results of statistically significant biomarker results must be treated with caution because natural variability in responses can occur even in the absence of toxicant exposure.
Jussi V K Kukkonen - One of the best experts on this subject based on the ideXlab platform.
-
effects of activated carbon on pcb bioaccumulation and biological responses of Chironomus Riparius in full life cycle test
Environmental Science & Technology, 2016Co-Authors: Inna Nybom, Sebastian Abel, Kimmo Mäenpää, Greta Waissi, Kristiina Vaananen, Matti T Leppanen, Jussi V K Kukkonen, Jarkko AkkanenAbstract:The nonbiting midge Chironomus Riparius was used to study the remediation potential and secondary effects of activated carbon (AC, o 63–200 μm) in PCB contaminated sediments. AC amendments efficiently reduced PCB bioavailability determined by Chironomus Riparius bioaccumulation tests and passive samplers. PCBs were shown to transfer from larvae to adults. Lower PCB concentrations were observed in adult midges emerging from AC amended compared to unamended sediments. Increased reproduction, survival, larval growth and gut wall microvilli length were observed with low AC dose (0.5% sediment dw) compared to unamended sediment, indicating an improved success of larvae in the sediment with low organic carbon content. On the other hand, higher AC doses (2.5% sediment dw) caused adverse effects on emergence and larval development. In addition, morphological changes in the gut wall microvilli layer were observed. This study showed that the secondary effects of AC amendments are dependent on the dose and the sedim...
-
fullerenes nc60 affect the growth and development of the sediment dwelling invertebrate Chironomus Riparius larvae
Environmental Pollution, 2015Co-Authors: Greta C Waissileinonen, Inna Nybom, Jarkko Akkanen, Matti T Leppanen, Kukka Pakarinen, Jussi V K KukkonenAbstract:Abstract The possible toxicity of nanoparticles (NPs) to aquatic organisms needs to be investigated for chronic effects at low concentrations. Chronic effects of carbon NPs, fullerenesC 60 , on the midges of Chironomus Riparius at different life stages on larvae and adult midges were investigated. Sediment associated fullerenesC 60 were studied by 10-day growth and 42-day emergence tests with artificial sediment at nominal concentration ranges 0.0004–80 mg/kg dry weight. The body length decreased in the lower tested concentrations (0.0025–20 mg/kg), but the effect vanished with higher concentrations. Delayed emergence rate observed at 0.5 mg/kg. The observed effects correlated with analyzed sediment particle sizes indicating that small agglomerates of fullerene have more significant effects on C . Riparius than larger agglomerates observed with higher C 60 doses. The results reveal that fullerene may pose risks to benthic organisms, emerging as changes in the ecotoxic parameters studied here which inflects by the survival of the population.
-
toxicity of fullerene c60 to sediment dwelling invertebrate Chironomus Riparius larvae
Environmental Toxicology and Chemistry, 2012Co-Authors: Greta C Waissileinonen, Jarkko Akkanen, Matti T Leppanen, Jussi V K Kukkonen, Elijah J Petersen, Kukka PakarinenAbstract:An environmentally realistic method to test fullerene (C60) toxicity to the benthic organism Chironomus Riparius was created by allowing suspended fullerenes to settle down, making a layer on top of the sediment. To test the hypothesis that higher food concentrations will reduce toxic responses, two food concentrations were tested (0.5 and 0.8% Urtica sp.) in sediment containing fullerene masses of 0.36 to 0.55 mg/cm2 using a 10-d chronic test. In the 0.5% food level treatments, there were significant differences in all growth-related endpoints compared with controls. Fewer effects were observed for the higher food treatment. Fullerene agglomerates were observed by electron microscopy in the gut, but no absorption into the gut epithelial cells was detected. In the organisms exposed to fullerenes, microvilli were damaged and were significantly shorter. The potential toxicity of fullerene to C. Riparius appears to be caused by morphological changes, inhibiting larval growth. Environ. Toxicol. Chem. 2012; 31: 2108–2116. © 2012 SETAC
-
Toxicity of fullerene (C60) to sediment‐dwelling invertebrate Chironomus Riparius larvae
Environmental Toxicology and Chemistry, 2012Co-Authors: Greta C. Waissi-leinonen, Jarkko Akkanen, Matti T Leppanen, Elijah J Petersen, Kukka Pakarinen, Jussi V K KukkonenAbstract:An environmentally realistic method to test fullerene (C60) toxicity to the benthic organism Chironomus Riparius was created by allowing suspended fullerenes to settle down, making a layer on top of the sediment. To test the hypothesis that higher food concentrations will reduce toxic responses, two food concentrations were tested (0.5 and 0.8% Urtica sp.) in sediment containing fullerene masses of 0.36 to 0.55 mg/cm2 using a 10-d chronic test. In the 0.5% food level treatments, there were significant differences in all growth-related endpoints compared with controls. Fewer effects were observed for the higher food treatment. Fullerene agglomerates were observed by electron microscopy in the gut, but no absorption into the gut epithelial cells was detected. In the organisms exposed to fullerenes, microvilli were damaged and were significantly shorter. The potential toxicity of fullerene to C. Riparius appears to be caused by morphological changes, inhibiting larval growth. Environ. Toxicol. Chem. 2012; 31: 2108–2116. © 2012 SETAC
-
Effects of indomethacin and propranolol on Chironomus Riparius and Physella (Costatella) acuta.
Ecotoxicology and Environmental Safety, 2011Co-Authors: Julio C. López-doval, Jussi V K Kukkonen, P. Rodrigo, Isabel MuñozAbstract:Abstract New analytical methods are available for detecting novel xenobiotic compounds in freshwater systems. Pharmaceuticals are suspected of having effects on freshwater biota at very low concentrations, although the nature of these effects remains unclear. Previous data from the Llobregat River revealed a positive statistical relationship between the biomass of benthic macroinvertebrates and the presence of certain non-steroidal anti-inflammatory drugs (NSAIDs) and beta-blockers. Here, experiments were conducted with the midge Chironomus Riparius and the freshwater snail Physella (Costatella) acuta in sediments and water, respectively. The sediments and water were treated with the pharmaceuticals propranolol and indomethacin, with the aims of assaying the effects of these compounds on the organisms and testing the statistical relationships observed in field. The variables measured were survival; C. Riparius biomass; and the carbon/nitrogen ratio, lipid content and fertility of freshwater snails. Indomethacin in treated sediments induced an increase in C. Riparius biomass, whereas propranolol inhibited growth, albeit at marginal statistical significance. By contrast, indomethacin in water had no effect on any of the parameters measured in P. acuta.