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1.
Sci Total Environ ; 781: 146691, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-34594059

RESUMEN

Levels of total mercury were measured in tissue of six species of migratory fish (alewife, American shad, blueback herring, rainbow smelt, striped bass, and sea lamprey), and in roe of American shad for two consecutive years collected from the Penobscot River or its estuary. The resultant mercury levels were compared to reference doses as established in the U.S. Environmental Protection Agency (EPA) Integrated Risk Information System and wildlife values. Mercury concentrations ranged from 4 µg/kg ww in roe to 1040 µg/kg ww in sea lamprey. Sea lamprey contained the highest amounts of mercury for both seasons of sampling. Current health advisories are set at sufficient levels to protect fishers from harmful consumption of the fish for mercury alone, except for sea lamprey. Based upon published wildlife values for mink, otter, and eagle, consumption of rainbow smelt, striped bass, or sea lamprey poses a risk to mink; striped bass and sea lamprey to otter; and sea lamprey to eagle. For future consideration, the resultant data may serve as a reference point for both human health and wildlife risk assessments for the consumption of anadromous fish. U.S. EPA works with federally recognized Tribes across the nation greatly impacted by restrictions on sustenance fishing, to develop culturally sensitive risk assessments.


Asunto(s)
Mercurio , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Estuarios , Peces , Humanos , Maine , Mercurio/análisis , Ríos , Contaminantes Químicos del Agua/análisis
2.
Environ Sci Technol ; 55(9): 5620-5628, 2021 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-33851533

RESUMEN

For decades, we have known that chemicals affect human and wildlife behavior. Moreover, due to recent technological and computational advances, scientists are now increasingly aware that a wide variety of contaminants and other environmental stressors adversely affect organismal behavior and subsequent ecological outcomes in terrestrial and aquatic ecosystems. There is also a groundswell of concern that regulatory ecotoxicology does not adequately consider behavior, primarily due to a lack of standardized toxicity methods. This has, in turn, led to the exclusion of many behavioral ecotoxicology studies from chemical risk assessments. To improve understanding of the challenges and opportunities for behavioral ecotoxicology within regulatory toxicology/risk assessment, a unique workshop with international representatives from the fields of behavioral ecology, ecotoxicology, regulatory (eco)toxicology, neurotoxicology, test standardization, and risk assessment resulted in the formation of consensus perspectives and recommendations, which promise to serve as a roadmap to advance interfaces among the basic and translational sciences, and regulatory practices.


Asunto(s)
Conservación de los Recursos Naturales , Ecotoxicología , Animales , Animales Salvajes , Ecosistema , Humanos , Medición de Riesgo
3.
Water (Basel) ; 12(5): 1-1496, 2020 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-32704397

RESUMEN

To better understand how the sulfate (SO4 2-) anion may contribute to the adverse effects associated with elevated ionic strength or salinity in freshwaters, we measured the uptake and efflux of SO4 2- in four freshwater species: the fathead minnow (Pimephales promelas, Teleostei: Cyprinidae), paper pondshell (Utterbackia imbecillis, Bivalvia: Unionidae), red swamp crayfish (Procambarus clarkii, Crustacea: Cambaridae), and two-lined mayfly (Hexagenia bilineata, Insecta: Ephemeridae). Using δ( 34 S/ 32 S) stable isotope ratios and the concentrations of S and SO4 2-, we measured the SO4 2- influx rate (J in ), net flux (J net ), and efflux rate (Jout) during a 24 h exposure period. For all four species, the means of J in for SO4 2- were positive, and J in was significantly greater than 0 at both target SO4 2- concentrations in the fish and mollusk and at the lower SO4 2- concentration in the crayfish. The means of J out and J net were much more variable than those for J in , but several species by target SO4 2- concentration combinations for J out and J net , were negative, which suggests the net excretion of SO4 2- by the animals. The results of our experiments suggest a greater regulation of SO4 2- in freshwater animals than has been previously reported.

4.
Environ Pollut ; 239: 706-713, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29715690

RESUMEN

Rivers in the arid Western United States face increasing influences from anthropogenic contaminants due to population growth, urbanization, and drought. To better understand and more effectively track the impacts of these contaminants, biologically-based monitoring tools are increasingly being used to complement routine chemical monitoring. This study was initiated to assess the ability of both targeted and untargeted biologically-based monitoring tools to discriminate impacts of two adjacent wastewater treatment plants (WWTPs) on Colorado's South Platte River. A cell-based estrogen assay (in vitro, targeted) determined that water samples collected downstream of the larger of the two WWTPs displayed considerable estrogenic activity in its two separate effluent streams. Hepatic vitellogenin mRNA expression (in vivo, targeted) and NMR-based metabolomic analyses (in vivo, untargeted) from caged male fathead minnows also suggested estrogenic activity downstream of the larger WWTP, but detected significant differences in responses from its two effluent streams. The metabolomic results suggested that these differences were associated with oxidative stress levels. Finally, partial least squares regression was used to explore linkages between the metabolomics responses and the chemical contaminants that were detected at the sites. This analysis, along with univariate statistical approaches, identified significant covariance between the biological endpoints and estrone concentrations, suggesting the importance of this contaminant and recommending increased focus on its presence in the environment. These results underscore the benefits of a combined targeted and untargeted biologically-based monitoring strategy when used alongside contaminant monitoring to more effectively assess ecological impacts of exposures to complex mixtures in surface waters.


Asunto(s)
Cyprinidae/metabolismo , Monitoreo del Ambiente/métodos , Estrógenos/análisis , Ríos/química , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisis , Animales , Colorado , Estrona/análisis , Masculino , Metabolómica , Vitelogeninas/metabolismo , Purificación del Agua/normas
5.
Environ Toxicol Chem ; 36(11): 3102-3107, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28631833

RESUMEN

The egg yolk precursor protein vitellogenin is widely used as a biomarker of estrogen exposure in male fish. However, standardized methodology is lacking and little is known regarding the reproducibility of results among laboratories using different equipment, reagents, protocols, and data analysis programs. To address this data gap we tested the reproducibility across laboratories to evaluate vitellogenin gene (vtg) expression and assessed the value of using a freely available software data analysis program. Samples collected from studies of male fathead minnows (Pimephales promelas) exposed to 17α-ethinylestradiol (EE2) and minnows exposed to processed wastewater effluent were evaluated for vtg expression in 4 laboratories. Our results indicate reasonable consistency among laboratories if the free software for expression analysis LinRegPCR is used, with 3 of 4 laboratories detecting vtg in fish exposed to 5 ng/L EE2 (n = 5). All 4 laboratories detected significantly increased vtg levels in 15 male fish exposed to wastewater effluent compared with 15 male fish held in a control stream. Finally, we were able to determine that the source of high interlaboratory variability from complementary deoxyribonucleic acid (cDNA) to quantitative polymerase chain reaction (qPCR) analyses was the expression analysis software unique to each real-time qPCR machine. We successfully eliminated the interlaboratory variability by reanalyzing raw fluorescence data with independent freeware, which yielded cycle thresholds and polymerase chain reaction (PCR) efficiencies that calculated results independently of proprietary software. Our results suggest that laboratories engaged in monitoring programs should validate their PCR protocols and analyze their gene expression data following the guidelines established in the present study for all gene expression biomarkers. Environ Toxicol Chem 2017;36:3102-3107. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.


Asunto(s)
Perfilación de la Expresión Génica/normas , Vitelogeninas/metabolismo , Animales , Cyprinidae/metabolismo , Estrógenos/toxicidad , Etinilestradiol/toxicidad , Expresión Génica , Masculino , Reacción en Cadena de la Polimerasa/normas , Control de Calidad , Reproducibilidad de los Resultados , Programas Informáticos , Vitelogeninas/genética , Aguas Residuales/química , Contaminantes Químicos del Agua/toxicidad
7.
Environ Sci Technol ; 51(5): 3021-3031, 2017 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-28230353

RESUMEN

U.S. EPA conducted a national statistical survey of fish tissue contamination at 540 river sites (representing 82 954 river km) in 2008-2009, and analyzed samples for 50 persistent organic pollutants (POPs), including 21 PCB congeners, 8 PBDE congeners, and 21 organochlorine pesticides. The survey results were used to provide national estimates of contamination for these POPs. PCBs were the most abundant, being measured in 93.5% of samples. Summed concentrations of the 21 PCB congeners had a national weighted mean of 32.7 µg/kg and a maximum concentration of 857 µg/kg, and exceeded the human health cancer screening value of 12 µg/kg in 48% of the national sampled population of river km, and in 70% of the urban sampled population. PBDEs (92.0%), chlordane (88.5%) and DDT (98.7%) were also detected frequently, although at lower concentrations. Results were examined by subpopulations of rivers, including urban or nonurban and three defined ecoregions. PCBs, PBDEs, and DDT occur at significantly higher concentrations in fish from urban rivers versus nonurban; however, the distribution varied more among the ecoregions. Wildlife screening values previously published for bird and mammalian species were converted from whole fish to fillet screening values, and used to estimate risk for wildlife through fish consumption.


Asunto(s)
Monitoreo del Ambiente , Ríos , Animales , Peces , Humanos , Hidrocarburos Clorados , Bifenilos Policlorados , Contaminantes Químicos del Agua
8.
Environ Res ; 151: 313-320, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27522569

RESUMEN

Influence of waterborne butachlor (BUC), a commonly used pesticide, on morphometric, biochemical, and molecular biomarkers was evaluated in juvenile, full sibling, diploid and triploid African catfish (Clarias gariepinus). Fish were exposed for 21 days to one of three concentrations of BUC [mean measured µg/L: 22, 44 or 60]. Unexposed (control) triploids were heavier and longer and had higher visceral-somatic index (VSI) than diploids. Also, they had lighter liver weight (HSI) and showed lower transcript levels of brain gonadotropin-releasing hormone (GnRH), aromatase (cyp191b) and fushi tarazu-factor (ftz-f1), and plasma testosterone levels than diploids. Butachlor treatments had no effects, in either diploid or triploid fish, on VSI, HSI, weight or length changes, condition factor (CF), levels of plasma testosterone, 17-ß estradiol (E2), cortisol, cholesterol, or mRNA levels of brain tryptophan hydroxylase (tph2), forkhead box L2 (foxl2), and 11 ß-hydroxysteroid dehydrogenase type 2 (11ß-hsd2). Expressions of cyp191b and ftz-f1 in triploids were upregulated by the two highest concentrations of BUC. In diploid fish, however, exposures to all BUC concentrations decreased GnRH transcription and the medium BUC concentration decreased ftz-f1 transcription. Substantial differences between ploidies in basal biomarker responses are consistent with the reported impaired reproductive axis in triploid C. gariepinus. Furthermore, the present study showed the low impact of short term exposure to BUC on reproductive axis in C. gariepinus.


Asunto(s)
Acetanilidas/toxicidad , Biomarcadores/sangre , Bagres , Animales , Diploidia , Femenino , Masculino , Triploidía
9.
Sci Total Environ ; 557-558: 204-11, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-26994807

RESUMEN

The impacts of environmental stressors on polyploid organisms are largely unknown. This study investigated changes in morphometric, molecular, and biochemical parameters in full-sibling diploid and triploid African catfish (Clarias gariepinus) in response to chlorpyrifos (CPF) exposures. Juvenile fish were exposed to three concentrations of CPF (mean measured µg/L (SD): 9.71 (2.27), 15.7 (3.69), 31.21 (5.04)) under a static-renewal condition for 21days. Diploid control groups had higher hepatosomatic index (HSI), plasma testosterone (T), and brain GnRH and cyp19a2 expression levels than triploids. In CPF-exposed groups, changes in HSI, total weight and length were different between the diploid and triploid fish. In contrast, condition factor did not alter in any of the treatments, while visceral-somatic index (VSI) changed only in diploids. In diploid fish, exposure to CPF did not change brain 11ß-hsd2, ftz-f1, foxl2, GnRH or cyp19a2 mRNA levels, while reduced tph2 transcript levels compared to the control group. In contrast, 11ß-hsd2 and foxl2 expression levels were changed in triploids following CPF exposures. In diploids, plasma T levels showed a linear dose-response reduction across CPF treatments correlating with liver weight and plasma total cholesterol concentrations. In contrast, no changes in plasma cholesterol and T concentrations were observed in triploids. Plasma cortisol and 17-ß estradiol (E2) showed no response to CPF exposure in either ploidy. Results of this first comparison of biomarker responses to pesticide exposure in diploid and polyploid animals showed substantial differences between diploid and triploid C. gariepinus.


Asunto(s)
Bagres/fisiología , Cloropirifos/toxicidad , Diploidia , Plaguicidas/toxicidad , Triploidía , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 2/metabolismo , Animales , Biomarcadores/metabolismo , Monitoreo del Ambiente , Estradiol/metabolismo , Hígado/metabolismo , Testosterona/metabolismo
10.
Environ Toxicol Chem ; 35(1): 6-13, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26771345

RESUMEN

In this Focus article, the authors ask a seemingly simple question: Are harmful algal blooms (HABs) becoming the greatest inland water quality threat to public health and aquatic ecosystems? When HAB events require restrictions on fisheries, recreation, and drinking water uses of inland water bodies significant economic consequences result. Unfortunately, the magnitude, frequency, and duration of HABs in inland waters are poorly understood across spatiotemporal scales and differentially engaged among states, tribes, and territories. Harmful algal bloom impacts are not as predictable as those from conventional chemical contaminants, for which water quality assessment and management programs were primarily developed, because interactions among multiple natural and anthropogenic factors determine the likelihood and severity to which a HAB will occur in a specific water body. These forcing factors can also affect toxin production. Beyond site-specific water quality degradation caused directly by HABs, the presence of HAB toxins can negatively influence routine surface water quality monitoring, assessment, and management practices. Harmful algal blooms present significant challenges for achieving water quality protection and restoration goals when these toxins confound interpretation of monitoring results and environmental quality standards implementation efforts for other chemicals and stressors. Whether HABs presently represent the greatest threat to inland water quality is debatable, though in inland waters of developed countries they typically cause more severe acute impacts to environmental quality than conventional chemical contamination events. The authors identify several timely research needs. Environmental toxicology, environmental chemistry, and risk-assessment expertise must interface with ecologists, engineers, and public health practitioners to engage the complexities of HAB assessment and management, to address the forcing factors for HAB formation, and to reduce the threats posed to inland surface water quality.


Asunto(s)
Ecosistema , Salud Ambiental , Floraciones de Algas Nocivas , Salud Pública , Calidad del Agua , Cambio Climático , Predicción , Agua Dulce , Humanos , Urbanización , Abastecimiento de Agua
11.
Chemosphere ; 144: 366-73, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26383263

RESUMEN

17α-ethinylestradiol (EE2) is a synthetic estrogen that is an active ingredient in oral contraception and hormone replacement therapy. Surveys of wastewater treatment plant effluents and surface waters throughout the world have reported EE2 concentrations in the ng/L range, and these low levels can cause significant reproductive effects in fish. This study tested the effects of three environmentally relevant EE2 concentrations: 0.47, 1.54 and 3.92 ng/L using a 21 d short-term reproductive assay to investigate the effects of EE2 on fathead minnow (Pimephales promelas) reproduction. The two highest EE2 concentrations tested in this study caused significant liver gene expression and induction of vitellogenin plasma protein in male fathead minnows. Exposure to 3.92 ng EE2/L increased the production of plasma vitellogenin in the females. Plasma estradiol concentrations were significantly reduced in females exposed to 1.54 and 3.92 ng EE2/L. All three tested concentrations significantly reduced fathead minnow egg production after a 21 d exposure to EE2. The results of this study indicate that the previously reported no observed adverse effect concentration (NOAEC) for EE2 on fathead minnow egg production (1.0 ng/L) may be too high. Because all three treatments resulted in significantly reduced egg production, the lowest observed adverse effect concentration (LOAEC) for EE2 on fathead minnow egg production is 0.47 ng EE2/L. This research estimates a NOAEC for fathead minnow reproduction at 0.24 ng EE2/L following a 21 d exposure. Additionally, induction of vitellogenin is a sensitive indicator of estrogen exposure but does not appear to be predictive of fathead minnow egg production.


Asunto(s)
Cyprinidae/fisiología , Estrógenos/toxicidad , Etinilestradiol/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Cyprinidae/sangre , Cyprinidae/genética , Estradiol/sangre , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Nivel sin Efectos Adversos Observados , Reproducción/efectos de los fármacos , Vitelogeninas/sangre
12.
Environ Toxicol Chem ; 35(4): 874-81, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26562077

RESUMEN

To assess the potential exposure of aquatic ecosystems to active pharmaceutical ingredients, the authors conducted a national-scale, probability-based statistical survey of the occurrence of these compounds in surface waters of the United States. The survey included 182 sampling sites and targeted rivers with close proximity to urban areas. The 46 analytes reported represent many classes of active pharmaceutical ingredients (APIs), including antibiotics, diuretics, antihypertensives, anticonvulsants, and antidepressants. Of the 46 analytes, 37 were detected in at least 1 sampling location. Sulfamethoxazole (an antibiotic) was the most frequently detected compound, being measured in 141 of the 182 surface waters surveyed at concentrations ranging up to 570 ng/L. Ten of the compounds were detected in 20% or more of the sampling sites. Weighted means of the analytical measurements are used with the statistical survey design and analysis to provide national estimates of the extent of contamination for these APIs in the nation's urban rivers. Published 2015 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US Government work and as such, is in the public domain in the United States of America.


Asunto(s)
Monitoreo del Ambiente , Preparaciones Farmacéuticas/análisis , Ríos/química , Encuestas y Cuestionarios , Contaminantes Químicos del Agua/análisis , Agua Potable/química , Farmacorresistencia Microbiana , Ecosistema , Sulfametoxazol/análisis , Estados Unidos
13.
Environ Toxicol Chem ; 34(12): 2796-802, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26088724

RESUMEN

Endocrine-disrupting chemicals (EDCs) such as 17α-ethynylestradiol, 17ß-estradiol, estrone, and para-nonylphenol have been measured in wastewater-treatment plant effluents, surface waters, sediments, and sludge and have been shown to induce liver-specific vitellogenin (vtg) messenger RNA in male fathead minnows (Pimephales promelas). The purpose of the present study was to establish minimal concentrations of select EDCs necessary to induce transcription of vtg in 48-h static renewal exposures, as measured by quantitative real-time thermal cycle amplification. Adult males were exposed to 17α-ethynylestradiol, 17ß-estradiol, estrone, and para-nonylphenol. Dose-dependent increases in vtg expression were significant with all chemicals tested. The lowest concentrations of these chemicals to induce measurable vtg expression, with significant difference from respective controls, were 17α-ethynylestradiol, 2.2 ng L(-1); para-nonylphenol, 13.9 µg L(-1); 17ß-estradiol, 42.7 ng L(-1); and estrone, 46.7 ng L(-1), measured as 48-h average concentrations. The present experiments were designed to frame a commonly acceptable approach for investigators who conduct static, in-laboratory proxy environmental aquatic exposures. The present study highlights the need for investigators to report in peer-reviewed submissions the observed concentration values for minimal induction levels when measuring molecular responses to chemical exposures by means of real-time polymerase chain reaction, quantitative polymerase chain reaction, or other "omic" technologies.


Asunto(s)
Cyprinidae/metabolismo , Disruptores Endocrinos/análisis , Monitoreo del Ambiente/métodos , Vitelogeninas/metabolismo , Contaminantes Químicos del Agua/análisis , Animales , Disruptores Endocrinos/toxicidad , Estradiol/metabolismo , Estradiol/toxicidad , Estrona/análisis , Estrona/toxicidad , Etinilestradiol/análisis , Etinilestradiol/toxicidad , Masculino , Fenoles/análisis , Fenoles/toxicidad , Aguas del Alcantarillado/química , Contaminantes Químicos del Agua/toxicidad
14.
Environ Toxicol Chem ; 34(6): 1277-82, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25663426

RESUMEN

The US Environmental Protection Agency (USEPA) develops methods and tools for evaluating risk management strategies for sediments contaminated with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and other legacy pollutants. Monitored natural recovery is a risk management alternative that relies on existing physical, chemical, and biological processes to contain, destroy, and/or reduce the bioavailability or toxicity of in-place contaminants. These naturally occurring processes are monitored to ensure that management and recovery are progressing as expected. One approach frequently used to evaluate the recovery of contaminated sediments and associated biota is the assessment of contaminant tissue levels, or body burden concentrations, in top trophic level fish. In the present study, aquatic invertebrates were examined as an indicator of recent exposure to PCBs. The approach aimed to determine whether invertebrates collected using artificial substrates (i.e., Hester-Dendy samplers) could be used to discriminate among contaminated sites through the analyses of PCBs in whole homogenates of macroinvertebrates. Macroinvertebrates were sorted, preserved, and analyzed for total PCBs (t-PCBs), by summing 107 PCB congeners. Macroinvertebrate body burden concentrations showed similar trends to sediment t-PCB concentrations at the sites sampled. The results indicate that macroinvertebrates can be used to assess sediment contamination among sites that have different PCB contamination levels.


Asunto(s)
Invertebrados/metabolismo , Lagos/química , Bifenilos Policlorados/análisis , Contaminantes Químicos del Agua/análisis , Animales , Monitoreo del Ambiente , Restauración y Remediación Ambiental , Cromatografía de Gases y Espectrometría de Masas , Sedimentos Geológicos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Estados Unidos
15.
Environ Toxicol Chem ; 34(6): 1267-76, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25565098

RESUMEN

In 2007, approximately 420,500 cubic meters of contaminated sediment were removed from the Ashtabula River by dredging. The primary objective of the present study was to monitor contaminant exposure in fish and macroinvertebrates before, during, and after dredging. This was done by measuring tissue concentrations of polychlorinated biphenyl (PCB) and polycyclic aromatic hydrocarbon (PAH) in brown bullhead catfish (Ameriurus nebulosa) and in benthic macroinvertebrates, assessing changes in DNA damage in fish liver and blood, and scoring external and histopathological lesions and anomalies in the fish. In surficial sediment PCBs and PAHs were also quantified in conjunction with the biological sampling. The results show a significant reduction in contaminant levels in both fish and macroinvertebrates following dredging, indicating the effectiveness of the remediation in reducing exposure of biota to the primary contaminants of concern. Similarly, DNA damage levels in fish collected from the Ashtabula River significantly declined following dredging; however, a similar reduction in DNA damage over time was seen in fish collected from a reference site (Conneaut Creek), making interpretation difficult. Macroinvertebrate PCB concentrations were reflective of the sediment concentrations in the areas where Hester-Dendy samplers were deployed for macroinvertebrate collection. The present study demonstrates that these methods can be used to evaluate and assess the effectiveness of remediation techniques at contaminated sediment sites.


Asunto(s)
Sedimentos Geológicos/química , Ictaluridae/metabolismo , Invertebrados/genética , Ríos/química , Animales , Daño del ADN/efectos de los fármacos , Monitoreo del Ambiente , Restauración y Remediación Ambiental , Cromatografía de Gases y Espectrometría de Masas , Invertebrados/metabolismo , Bifenilos Policlorados/análisis , Bifenilos Policlorados/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
16.
Chemosphere ; 139: 597-603, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24932778

RESUMEN

Criteria for establishing water quality standards that are protective for 95% of the native species are generally based upon laboratory toxicity tests. These tests utilize common model organisms that have established test methods. However, for invertebrates these species represent mostly the zooplankton community and are not inclusive of all taxa. In order to examine a potential under-representation in emerging aquatic invertebrates the US Environmental Protection Agency has cultured a parthenogenetic mayfly, Centroptilum triangulifer (Ephemeroptera: Baetidae). This study established a 48h acute and a 14-day short-term chronic testing procedure for C. triangulifer and compared its sensitivity to two model invertebrates, Ceriodaphnia dubia and Daphnia magna. Toxicity tests were conducted to determine mortality and growth effects using standard reference toxicants: NaCl, KCl and CuSO4. In 48-h acute tests, the average LC50 for the mayfly was 659mgL(-1) NaCl, 1957mgL(-1) KCl, and 11µgL(-1) CuSO4. IC25 values, using dry weight as the endpoint, were 228mgL(-1) NaCl, 356mgL(-1) KCl and 5µgL(-1) CuSO4. C. triangulifer was the most sensitive species in NaCl acute and chronic growth tests. At KCl concentrations tested, C. triangulifer was less sensitive for acute tests but was equally or more sensitive than C. dubia and D. magna for growth measurements. This study determined C. triangulifer has great potential and benefits for use in ecotoxicological studies.


Asunto(s)
Sulfato de Cobre/toxicidad , Daphnia/efectos de los fármacos , Ephemeroptera/efectos de los fármacos , Cloruro de Potasio/toxicidad , Cloruro de Sodio/toxicidad , Pruebas de Toxicidad/normas , Contaminantes Químicos del Agua/toxicidad , Animales , Estándares de Referencia
17.
Environ Toxicol Chem ; 34(1): 167-72, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25307284

RESUMEN

Anthropogenic disturbances, including those from developing energy resources, can alter stream chemistry significantly by elevating total dissolved solids. Field studies have indicated that mayflies (Order Ephemeroptera) are particularly sensitive to high total dissolved solids. In the present study, the authors measured 20-d growth and survivorship of larval Neocloeon triangulifer exposed to a gradient of brine salt (mixed NaCl and CaCl2 ) concentrations. Daily growth rates were reduced significantly in all salt concentrations above the control (363 µS cm(-1) ) and larvae in treatments with specific conductance >812 µS cm(-1) were in comparatively earlier developmental stages (instars) at the end of the experiment. Survivorship declined significantly when specific conductance was >1513 µS cm(-1) and the calculated 20-d 50% lethal concentration was 2866 µS cm(-1) . The present study's results provide strong experimental evidence that elevated ion concentrations similar to those observed in developing energy resources, such as oil and gas drilling or coal mining, can adversely affect sensitive aquatic insect species.


Asunto(s)
Cloruro de Calcio/toxicidad , Ephemeroptera/efectos de los fármacos , Cloruro de Sodio/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Cloruro de Calcio/análisis , Ephemeroptera/química , Ephemeroptera/crecimiento & desarrollo , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Larva/metabolismo , Cloruro de Sodio/análisis , Pruebas de Toxicidad , Contaminantes Químicos del Agua/análisis
18.
Chemosphere ; 139: 589-96, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24894451

RESUMEN

Development of methods for assessing exposure and effects of waterborne toxicants on stream invertebrate species is important to elucidate environmentally relevant information. Current protocols for freshwater invertebrate toxicity testing almost exclusively utilize cladocerans, amphipods or chironomids rather than the more typical aquatic insect taxa found in lotic systems. Centroptilum triangulifer is a parthenogenetic mayfly occurring in depositional habitats of streams and rivers of the Eastern U.S. and Canada. C. triangulifer is an ideal stream insect for toxicity testing under field and laboratory conditions because of its short life cycle, parthenogenetic mode of reproduction, and it represents a group considered sensitive to environmental stressors. In this study, a colony of C. triangulifer was reared using a defined diet of three diatoms, Mayamaea atomus var. permitis, Nitzschia cf. pusilla, and Achnanthidium minutissimum. Percent survival (⩾80%), fecundity measurements (⩾1000 eggs) and pre-egg laying weights were used as indicators of overall colony health and fitness in our laboratory water (Lab-line) and in Moderately Hard Reconstituted Water (MHRW). Lab-line reared C. triangulifer had average survival rate of 92.69% for eleven generations and 82.99% over thirteen generations. MHRW reared C. triangulifer had an average survival rate of 80.65% for four generations and three generations of fecundities greater than 1000 eggs per individual. Pre-egg laying weight and fecundity were highly correlated and a best-fit model equation was derived to estimate egg counts for future generations. Establishment of this culturing protocol provides a more ecologically relevant species for toxicity testing and aids in further stressor identification for stream bioassessments.


Asunto(s)
Técnicas de Cultivo/métodos , Diatomeas , Dieta , Ephemeroptera/crecimiento & desarrollo , Laboratorios , Animales , Peso Corporal , Ecosistema , Ephemeroptera/fisiología , Femenino , Fertilidad , Oviposición , Ríos , Análisis de Supervivencia , Pruebas de Toxicidad
19.
Chemosphere ; 120: 108-14, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25014901

RESUMEN

Aquatic organisms are exposed to a multitude of contaminants and to fully understand the impact of multiple stressors on fish populations, we must first understand the mechanism of action for each toxicant and how the combined effects manifest at the level of the individual. 17α-ethinylestradiol (EE2) has been known to cause adverse reproductive effects including reduced fecundity and fertility, intersex and skewed sex ratios in fish by mimicking naturally produced estrogen at low concentrations. Ammonia can cause adverse reproductive and mortality effects in individual fish through effects or damage to the central nervous system. Both EE2 and ammonia are found in most municipal effluents in various concentrations. A flow-through diluter system was used to test the individual effects of these two contaminants at their respective no observable adverse effect concentration (NOAEC) as well as their combined effects on fathead minnow, (Pimephales promelas) reproduction in a mixture exposure. While neither contaminant nor their mixture altered reproduction in terms of fecundity, their mixture resulted in significant fathead minnow mortality during a 21 d exposure. This study demonstrated the need to consider mixture effects when assessing risk for toxicity testing with multiple stressors.


Asunto(s)
Amoníaco/toxicidad , Cyprinidae/crecimiento & desarrollo , Disruptores Endocrinos/toxicidad , Etinilestradiol/toxicidad , Reproducción/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Amoníaco/análisis , Animales , Cyprinidae/fisiología , Disruptores Endocrinos/análisis , Etinilestradiol/análisis , Femenino , Masculino , Razón de Masculinidad , Pruebas de Toxicidad , Vitelogeninas/metabolismo , Contaminantes Químicos del Agua/análisis
20.
Chemosphere ; 122: 52-61, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25434269

RESUMEN

The U.S. EPA conducted a national statistical survey of fish fillet tissue with a sample size of 541 sites on boatable rivers =>5th order in 2008-2009. This is the first such study of mercury (Hg) in fish tissue from river sites focused on potential impacts to human health from fish consumption to also address wildlife impacts. Sample sites were identified as being urban or non-urban. All sample mercury concentrations were above the 3.33ugkg(-1) (ppb) quantitation limit, and an estimated 25.4% (±4.4%) of the 51663 river miles assessed exceeded the U.S. EPA 300ugkg(-1) fish-tissue based water quality criterion for mercury, representing 13144±181.8 river miles. Estimates of river miles exceeding comparable aquatic life thresholds (translated from fillet concentrations to whole fish equivalents) in avian species were similar to the number of river miles exceeding the human health threshold, whereas some mammalian species were more at risk than human from lower mercury concentrations. A comparison of means from the non-urban and urban data and among three ecoregions did not indicate a statistically significant difference in fish tissue Hg concentrations at p<0.05.


Asunto(s)
Peces , Contaminación de Alimentos/análisis , Mercurio/análisis , Contaminantes Químicos del Agua/análisis , Animales , Monitoreo del Ambiente/estadística & datos numéricos , Ríos , Estados Unidos , United States Environmental Protection Agency
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