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ABSTRACT: In September 2007, Lake Davis (near Portola, California) was treated by the California Department of Fish and Game with CFT Legumine, a rotenone formulation, to eradicate the invasive northern pike (Esox lucius). The objective of this report is to describe the fate of the five major formulation constituents-rotenone, rotenolone, methyl pyrrolidone (MP), diethylene glycol monethyl ether (DEGEE), and Fennedefo 99-in water, sediment, and brown bullhead catfish (Ameiurus nebulosus; a rotenone-resistant species) by determination of their half-lives (t(1/2)) and pseudo first-order dissipation rate constants (k). The respective t(1/2) values in water for rotenone, rotenolone, MP, DEGEE, and Fennedefo 99 were 5.6, 11.1, 4.6, 7.7, and 13.5 d; in sediments they were 31.1, 31.8, 10.0, not able to calculate, and 48.5 d; and in tissues were 6.1, 12.7, 3.7, 3.2, and 10.4 d, respectively. Components possessing low water solubility values (rotenone and rotenolone) persisted longer in sediments (not detectable after 157 d) and tissues (<212 d) compared with water, whereas the water-miscible components (MP and DEGEE) dissipated more quickly from all matrices, except for Fennedefo 99, which was the most persistent in water (83 d). None of the constituents was found to bioaccumulate in tissues as a result of treatment. In essence, the physicochemical properties of the chemical constituents effectively dictated their fate in the lake following treatment.
Environmental Toxicology and Chemistry 03/2012; 31(5):1032-41. · 2.81 Impact Factor
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April R Van Scoy,
Brian S Anderson,
Bryn M Philips,
Jennifer Voorhees,
Marguerite McCann,
Hector De Haro,
Marida J Martin,
James McCall,
Charles R Todd, David Crane,
Michael L Sowby,
Ronald S Tjeerdema
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ABSTRACT: Oil spill responders require information on the relative toxicity of dispersed and un-dispersed oil in order to make informed decisions regarding the use of chemical dispersants during spill events. Toxicity of the water-accommodated fraction (WAF) and the chemically-enhanced WAF (CEWAF; via the dispersant Corexit 9500) of weathered Prudhoe Bay crude oil was investigated using adult and embryonic topsmelt; topsmelt are an ecologically important atherinid in California bays and estuaries and an important indicator species. Following 96-h exposures, metabolite profiles were measured using 1D (1)H nuclear magnetic resonance (NMR) spectroscopy and compared via principal component analysis. Similar metabolic profiles were obtained between WAF- and CEWAF-exposed adults and embryos. Although metabolic changes, for the adults lacked significance, significant increasing and decreasing metabolic changes were observed for embryos directly exposed. Furthermore, no mortality was observed for embryos, exposed to WAF and normal development occurred, whereas CEWAF exposed embryos lead to mortality and cardiovascular abnormalities. Observed toxicological information, specifically for developing fish, can aide resource managers in the relative risk of treating oil spills with dispersant.
Ecotoxicology and Environmental Safety 12/2011; 78:99-109. · 2.29 Impact Factor
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ABSTRACT: Irrigation and storm water runoff from agricultural fields has the potential to cause impairment to downstream aquatic receiving systems. Over the last several years, scientists have discovered the benefit of using edge-of-field practices, such as vegetated agricultural drainage ditches, in the mitigation of pesticides and sediment. After demonstrating this practice's feasibility in California, field trials were initiated to document irrigation runoff pesticide mitigation in California alfalfa and tomato fields. In the alfalfa field, chlorpyrifos concentration was decreased by 20% from the inflow to the ditch outflow. Thirty-two percent of the measured chlorpyrifos mass was associated with ditch plant material. In the tomato field, permethrin concentration was decreased by 67% and there was a 35% reduction in suspended sediment concentration from inflow to the ditch outflow. When surface water was not present in the ditch systems, the sediment was a significant repository for pesticides. Based on the field trials, vegetated agricultural drainage ditches can be successfully used as part of a suite of management practices to reduce pesticide and sediment runoff into aquatic receiving systems.
Environmental Toxicology and Chemistry 02/2011; 30(5):1044-9. · 2.81 Impact Factor
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ABSTRACT: The current study investigated the potential of vegetated drainage ditches for mitigating the impact of agricultural irrigation runoff on downstream aquatic ecosystems. Water column toxicity to larval fathead minnow (Pimephales promelas),and the amphipod Hyalella azteca was measured for 12 h or less at the ditch inflow and outflow, using custom-built in situ exposure systems. In addition, water and sediment samples were subject to standard toxicity tests with Ceriodaphnia dubia and H. azteca, respectively. No acute toxicity to larval fathead minnow was observed; however, runoff was highly toxic to invertebrates. Passage through a 389- to 402-m section of vegetated ditch had a mitigating effect and reduced toxicity to some degree. However, runoff from an alfalfa field treated with chlorpyrifos remained highly toxic to both invertebrate species, and runoff from a tomato field treated with permethrin remained highly toxic to H. azteca after passage through the ditch. Predicted toxic units calculated from insecticide concentrations in runoff and 96-h median lethal concentration (LC50) values generally agreed with C. dubia toxicity measured in the laboratory but significantly underestimated in situ toxicity to H. azteca. Sediments collected near the ditch outflow were toxic to H. azteca. Results from the current study demonstrate that experimental vegetated ditches were unable to eliminate the risk of irrigation runoff to aquatic ecosystems. In addition, protective measures based on chemical concentrations or laboratory toxicity tests with C. dubia do not ensure adequate protection of aquatic ecosystems from pyrethroid-associated toxicity.
Environmental Toxicology and Chemistry 12/2010; 29(12):2859-68. · 2.81 Impact Factor
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April R Van Scoy,
Ching Yu Lin,
Brian S Anderson,
Bryn M Philips,
Marida J Martin,
James McCall,
Charles R Todd, David Crane,
Michael L Sowby,
Mark R Viant,
Ronald S Tjeerdema
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ABSTRACT: Crude oil spills from tankers remain a serious threat along coastal California. Resource managers require information on the acute toxicity of treated and untreated oil, and their sublethal effects on wildlife. This investigation compared the toxic actions of the water-accommodated fraction (WAF) and the chemically-enhanced WAF (CEWAF; Corexit 9500) of Prudhoe Bay crude oil in pre-smolt Chinook salmon (Oncorhynchus tshawytscha) via nuclear magnetic resonance (NMR)-based metabolomics. Metabolite profiles from muscle samples, after 96h exposures, were measured using 1D (1)H NMR and compared via principal component analysis. It was determined that both WAF and CEWAF produced similar profiles in which amino acids, lactate and ATP comprised the highest intensity signals. Overall, metabolic substrates and growth measurements did not show residual effects of short-term exposure on long-term development. In conclusion, the 96h LC(50)s indicate dispersant application significantly decreased hydrocarbon potency and identified metabolites may be bio-indicators of hydrocarbon stress from hydrocarbon exposure.
Ecotoxicology and Environmental Safety 04/2010; 73(5):710-7. · 2.29 Impact Factor
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Ching Yu Lin,
Brian S Anderson,
Bryn M Phillips,
Andrew C Peng,
Sara Clark,
Jennifer Voorhees,
Hong-Dar I Wu,
Marida J Martin,
James McCall,
Charles R Todd,
Fushing Hsieh, David Crane,
Mark R Viant,
Michael L Sowby,
Ronald S Tjeerdema
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ABSTRACT: With maritime transport of crude oil from Alaska to California, there is significant potential for a catastrophic spill which could impact migrating salmon. Therefore, this study compared the lethal and sublethal metabolic actions of the water-accommodated fraction (WAF) and the chemically enhanced WAF (CEWAF, via Corexit 9500) of Prudhoe Bay crude oil in smolts of Chinook salmon (Onchorhyncus tshawytscha). After 96-h exposure to the CEWAF, the resulting LC50 was some 20 times higher (i.e., less toxic) than that of the WAF. Muscle and liver samples from surviving fish were collected and low-molecular weight metabolites were analyzed using one-dimensional (1)H and projections of two-dimensional (1)H J-resolved NMR. Principal component analysis (PCA), employed to analyze NMR spectra and identify most variance from the samples, revealed age-related metabolic changes in the fish within the replicated studies, but few consistent metabolic effects from the treatments. However, ANOVA results demonstrated that the dose-response metabolite patterns are both metabolite- and organ-dependent. In general, exposure to either WAF or CEWAF resulted in an increase of amino acids (i.e., valine, glutamine and glutamate) and a decrease of both organic osmolytes (i.e., glycerophosphorylcholine) and energetic substrates (i.e., succinate). The simultaneous increase of formate and decrease of glycerophosphorylcholine in the liver, or the decrease of glycerophosphorylcholine in muscle, may serve as sensitive sublethal biomarkers for WAF or CEWAF exposures, respectively. In conclusion, dispersant treatment significantly decreased the lethal potency of crude oil to salmon smolts, and the NMR-based metabolomics approach provided a sensitive means to characterize the sublethal metabolic actions.
Aquatic toxicology (Amsterdam, Netherlands) 11/2009; 95(3):230-8. · 3.12 Impact Factor
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ABSTRACT: Static exposure experiments were conducted to assess the toxicity of dispersed Prudhoe Bay Crude Oil (PBCO) to embryos of the topsmelt (Atherinops affinis). Treatment with the dispersant COREXIT 9500 resulted in greater hydrocarbon concentrations in chemically enhanced water-accommodated fractions (CEWAFs) of oil, relative to the untreated water-accommodated fractions (WAFs). Topsmelt embryo development and survival to hatching was significantly inhibited in CEWAF tests while minimal effects on embryo-larval survival were observed in WAF tests. Increased hydrocarbon concentrations in the CEWAF tests caused cardiovascular and other abnormalities in developing topsmelt embryos.
Environmental pollution (Barking, Essex: 1987) 12/2008; 157(3):1058-61. · 3.43 Impact Factor
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ABSTRACT: To appraise existing evidence for prolotherapy, polidocanol, autologous whole blood and platelet-rich plasma injection therapies for lateral epicondylosis (LE).
Systematic review.
Medline, Embase, CINAHL, Cochrane Central Register of Controlled Trials, Allied and Complementary Medicine. Search strategy: names and descriptors of the therapies and LE.
All human studies assessing the four therapies for LE.
Results of five prospective case series and four controlled trials (three prolotherapy, two polidocanol, three autologous whole blood and one platelet-rich plasma) suggest each of the four therapies is effective for LE. In follow-up periods ranging from 9 to 108 weeks, studies reported sustained, statistically significant (p<0.05) improvement in visual analogue scale primary outcome pain score measures and disease-specific questionnaires; relative effect sizes ranged from 51% to 94%; Cohen's d ranged from 0.68 to 6.68. Secondary outcomes also improved, including biomechanical elbow function assessment (polidocanol and prolotherapy), presence of abnormalities and increased vascularity on ultrasound (autologous whole blood and polidocanol). Subjects reported satisfaction with therapies on single-item assessments. All studies were limited by small sample size.
There is strong pilot-level evidence supporting the use of prolotherapy, polidocanol, autologous whole blood and platelet-rich plasma injections in the treatment of LE. Rigorous studies of sufficient sample size, assessing these injection therapies using validated clinical, radiological and biomechanical measures, and tissue injury/healing-responsive biomarkers, are needed to determine long-term effectiveness and safety, and whether these techniques can play a definitive role in the management of LE and other tendinopathies.
British journal of sports medicine 12/2008; 43(7):471-81. · 2.55 Impact Factor
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ABSTRACT: Estrogenic potencies of four herbicides (triclopyr, 2,4-dichlorophenoxyacetic acid (2,4-D), diquat dibromide, glyphosate), two alkylphenol ethoxylate-containing surfactants (R-11 and Target Prospreader Activator (TPA)), and the binary mixture of surfactants with the herbicides were evaluated using an in vivo rainbow trout vitellogenin assay. Juvenile rainbow trout exposed to 2,4-D (1.64 mg/l) for 7 days had a 93-fold increase in plasma vitellogenin (Vtg) levels compared with untreated fish, while rainbow trout exposed to other pesticides alone did not show elevated vitellogenin levels compared to the control fish. When combined with surfactants, trends indicated enhanced estrogenicity for all combinations, but only 2,4-D and triclopyr caused significant induction of Vtg. Concentration-response studies demonstrated that the lowest observed effect concentrations (LOECs) for 2,4-D and triclopyr were 0.164 mg/l and 1 mg/l, respectively. In terms of measured 4-nonylphenol (4-NP), the LOECs of R-11 and TPA were 20 micro/l and 9.5 microg/l, respectively. Binary mixtures of TPA and 2,4-D showed a greater than additive estrogenic response at the lowest concentrations tested, but a less than additive response at the highest combined concentrations. Binary mixtures of TPA with triclopyr also caused greater than additive Vtg responses in two middle concentrations when compared to TPA or triclopyr alone. When trout were exposed to water collected from a site where triclopyr was used in combination with TPA, a concentration-dependent increase in Vtg expression was observed. Measured values of 4-NP were 3.7 microg/l, and triclopyr concentrations were below detection (<5 ng/l). Estradiol equivalents (EEQs) of the lake water were calculated from an estradiol concentration-response curve and were similar (8.5 +/- 7.7 ng/l) to the mean values for the combined triclopyr + TPA treatments (9.9-12.2 ng/l) in the laboratory, suggesting the estrogenicity of the water may have been due to the treatment. These results demonstrated the binary mixture of alkylphenol ethoxylate-containing surfactants with two aquatic pesticides possessed greater than additive estrogenic responses in fish under laboratory conditions and in a field setting.
Toxicological Sciences 11/2005; 87(2):391-8. · 4.65 Impact Factor
