Improvements inCryptosporidiumrecovery and variability through modifications to United States Environmental Protection Agency Method 1623

2012 ◽  
Vol 27 (2) ◽  
pp. 269-274 ◽  
Author(s):  
Gina Kimble ◽  
James Amburgey ◽  
Helene Hilger
Keyword(s):  
United States ◽  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Protection Agency ◽  
Method 1623 ◽  
Environmental Protection Agency Method

scholarly journals Identification of Particle Size Classes Inhibiting Protozoan Recovery from Surface Water Samples via U.S. Environmental Protection Agency Method 1623

2009 ◽  
Vol 75 (20) ◽  
pp. 6619-6621 ◽  
Author(s):  
Leigh-Anne H. Krometis ◽  
Gregory W. Characklis ◽  
Mark D. Sobsey
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Protection Agency ◽  
Method Performance ◽  
Species Recovery ◽  
Inorganic Particles ◽  
Method 1623 ◽  
Particle Size Classes ◽  
Surface Water Samples ◽  
Environmental Protection Agency Method

ABSTRACT Giardia species recovery by U.S. Environmental Protection Agency method 1623 appears significantly impacted by a wide size range (2 to 30 μm) of particles in water and organic matter. Cryptospori dium species recovery seems negatively correlated only with smaller (2 to 10 μm), presumably inorganic particles. Results suggest constituents and mechanisms interfering with method performance may differ by protozoan type.

scholarly journals Effects of Seeding Procedures and Water Quality on Recovery of Cryptosporidium Oocysts from Stream Water by Using U.S. Environmental Protection Agency Method 1623

2004 ◽  
Vol 70 (7) ◽  
pp. 4118-4128 ◽  
Author(s):  
Donna S. Francy ◽  
Otto D. Simmons ◽  
Michael W. Ware ◽  
Emma J. Granger ◽  
Mark D. Sobsey ◽  
...  
Keyword(s):  
Environmental Protection ◽  
Suspended Sediment ◽  
Environmental Protection Agency ◽  
Environmental Samples ◽  
Stream Water ◽  
Recovery Efficiency ◽  
Protection Agency ◽  
Method 1623 ◽  
Highly Correlated ◽  
Environmental Protection Agency Method

ABSTRACT U.S. Environmental Protection Agency method 1623 is widely used to monitor source waters and drinking water supplies for Cryptosporidium oocysts. Matrix spikes, used to determine the effect of the environmental matrix on the method's recovery efficiency for the target organism, require the collection and analysis of two environmental samples, one for analysis of endemic oocysts and the other for analysis of recovery efficiency. A new product, ColorSeed, enables the analyst to determine recovery efficiency by using modified seeded oocysts that can be differentiated from endemic organisms in a single sample. Twenty-nine stream water samples and one untreated effluent sample from a cattle feedlot were collected in triplicate to compare modified seeding procedures to conventional seeding procedures that use viable, unmodified oocysts. Significant negative correlations were found between the average oocyst recovery and turbidity or suspended sediment; this was especially apparent in samples with turbidities greater than 100 nephelometric turbidity units and suspended sediment concentrations greater than 100 mg/liter. Cryptosporidium oocysts were found in 16.7% of the unseeded environmental samples, and concentrations, adjusted for recoveries, ranged from 4 to 80 oocysts per 10 liters. Determining recovery efficiency also provided data to calculate detection limits; these ranged from <2 to <215 oocysts per 10 liters. Recoveries of oocysts ranged from 2.0 to 61% for viable oocysts and from 3.0 to 59% for modified oocysts. The recoveries between the two seeding procedures were highly correlated (r = 0.802) and were not significantly different. Recoveries by using modified oocysts, therefore, were comparable to recoveries by using conventional seeding procedures.

scholarly journals Cryptosporidium and Giardia Recoveries in Natural Waters by Using Environmental Protection Agency Method 1623

2002 ◽  
Vol 68 (12) ◽  
pp. 5952-5955 ◽  
Author(s):  
Carol L. DiGiorgio ◽  
David A. Gonzalez ◽  
Christopher C. Huitt
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Natural Waters ◽  
Control Sample ◽  
Monitoring Program ◽  
High Volume ◽  
Ambient Conditions ◽  
Protection Agency ◽  
Method 1623 ◽  
Environmental Protection Agency Method

ABSTRACT Relatively few studies have examined recoveries from source waters by using Environmental Protection Agency method 1623 with organism spike doses that are environmentally realistic and at turbidity levels commonly found in surface waters. In this study, we evaluated the filtration capacities and recovery efficiencies of the Gelman Envirochek (standard filter) and the Gelman Envirochek high-volume (HV) sampling capsules under environmental conditions. We also examined the performance of method 1623 under ambient conditions with matrix spike experiments using 10 organisms/liter. Under turbid conditions, the HV capsule filtered approximately twice the volume filtered by the standard filter, but neither could filter 10 liters without clogging. In low-turbidity waters, oocyst, but not cyst, recoveries were significantly higher when the HV capsule was used. In turbid waters, organism recoveries were lower than those in nonturbid waters and were not significantly different for the different filters. When the HV capsule was used, Cryptosporidium recoveries ranged from 36 to 75%, and Giardia recoveries ranged from 0.5 to 53%. For both organisms, recoveries varied significantly by site. Turbidity could explain variation in Giardia recoveries (r 2 = 0.80) but not variation in Cryptosporidium recoveries (r 2 = 0.16). The inconsistent recoveries across sites suggested that the background matrix of the ambient water affected recovery by method 1623. A control sample collected at the height of the winter rainy season detected one organism, highlighting the difficulty of using this method to accurately measure pathogen abundance under natural conditions. Our findings support the use of the HV filter under field conditions but suggest that designing a cost-effective and statistically valid monitoring program to evaluate sources and loads of protozoan pathogens may be difficult.

scholarly journals Presencia de plaguicidas organoclorados en forraje para ganado en unidades de producción de leche orgánica en Tecpatán, Chiapas

2017 ◽  
Vol 8 (2) ◽  
pp. 157 ◽  
Author(s):  
María N Murga Juárez ◽  
Rey Gutiérrez Tolentino ◽  
Salvador Vega y León ◽  
José J Pérez González ◽  
Beatriz Schettino Bermúdez ◽  
...  
Keyword(s):  
United States ◽  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Protection Agency ◽  
Codex Alimentarius

La presencia de plaguicidas organoclorados en el ambiente es preocupante por su persistencia, potencial de transporte a larga distancia y grado de toxicidad para la fauna y los seres humanos. En México, Chiapas ocupa el primer lugar en la producción de alimentos orgánicos, y Tecpatán es el principal municipio productor de leche orgánica. El objetivo de este trabajo fue determinar la presencia de plaguicidas organoclorados en forraje para ganado lechero en unidades de producción de leche orgánica. Se eligieron tres unidades de producción de leche orgánica y se colectaron muestras de forraje y leche en cada unidad. Los plaguicidas se extrajeron y purificaron con base en lo establecido por la USEPA (United States Environmental Protection Agency) y se analizaron por cromatografía de gases con detector de captura de electrones. Los compuestos que rebasaron el límite máximo permisible según el Codex Alimentarius fueron lindano, heptacloro + epóxido de heptacloro y aldrín + dieldrín (37.5 ± 84, 62 ± 125 y 20 ± 50 ng.g-1 base grasa, respectivamente). En las muestras de forraje los valores más altos fueron alfa + beta-HCH, lindano y heptacloro + epóxido de heptacloro (76.3 ± 140, 43 ± 105 ng.g-1 y 40 ± 76 ng.g-1 peso seco). Es probable que la destacada presencia de estos compuestos se deba a su utilización en el control de vectores en campañas de salud o de ectoparásitos del ganado de la región por parte de productores convencionales.

The Volkswagen Emissions Scandal

2016 ◽  
pp. 1-17
Author(s):  
Luann J. Lynch ◽  
Almand R. Coleman ◽  
Cameron Cutro ◽  
Cameron Cutro
Keyword(s):  
United States ◽  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Protection Agency ◽  
Top Executives ◽  
Performance Targets ◽  
The World ◽  
Hazardous Gases ◽  
And Performance ◽  
The U.S

In September 2015, VW had admitted to United States regulators that it had deliberately installed “defeat devices” in many of its diesel cars, which enabled the cars to cheat on federal and state emissions tests, making them able to pass the tests and hit ambitious mileage and performance targets while actually emitting up to 40 times more hazardous gases into the atmosphere than legally allowed. The discovery had prompted the U.S. Environmental Protection Agency (EPA) to halt final certification of VW’s 2016 diesel models, and VW itself had halted sales of its 2015 models. As fallout from the defeat devices developed, VW posted its first quarterly loss in more than 15 years, and its stock plummeted. Top executives were replaced, and VW abandoned its goal of becoming the world’s largest automaker. Stakeholders around the world had been asking since the scandal broke: “How could this have happened at Volkswagen?”

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