A Comparison of Current Methods for the Determination of Ra-226 and Ra-228 in Water by a Modified Georgia Tech Gamma Method Versus US Environmental Protection Agency Drinking Water Methodologies

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Dao M. Nguyen ◽  
W. Allen Moody ◽  
John A. Williamson
Keyword(s):  
Drinking Water ◽  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Georgia Tech ◽  
Protection Agency ◽  
Gamma Method

The Use of Aniline Blue for the Determination of Dead Phytoplankton, Zooplankton and Meroplankton in LC50 Testings After 96 Hours… A Re-Evaluation of the US Environmental Protection Agency Methodology

2004 ◽  
Vol 126 (3) ◽  
pp. 215-218 ◽  
Author(s):  
Balram Seepersad ◽  
Kelvin Ramnath ◽  
Shyam Dyal ◽  
Reeza Mohammed
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Staining Technique ◽  
Aniline Blue ◽  
Protection Agency ◽  
Lc50 Value ◽  
The Us ◽  
Visual Observations

There is a need for a reliable staining technique to distinguish between live and dead organisms following LC50 tests. This is especially so in cases where organisms can be stressed or even become unconscious and appear dead to the aided or naked eyes. Visual observations under such conditions can result in an LC50 value shifting to the lower concentration thereby imposing stiffer guidelines for compliance. Aniline blue can only stain individuals which are physiologically dead imposing an accurate live-dead evaluation and producing a true LC50 value. Guidelines imposed using such data will facilitate compliance and provide an accurate value for an LC50.

Skin Penetration Method Suggested for Environmental Protection Agency Requirements

1989 ◽  
Vol 8 (5) ◽  
pp. 829-835 ◽  
Author(s):  
Robert P. Zendzian
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Skin Penetration ◽  
Dermal Absorption ◽  
Male Rats ◽  
Application Site ◽  
Protection Agency ◽  
Blood Concentrations ◽  
Total Urine

The Environmental Protection Agency has circulated a protocol for examining the dermal absorption of pesticides in rats. This protocol will be considered as a guideline for determining the dermal absorption of pesticides. Approximately 40 pesticides have been evaluated with this protocol. Male rats are dosed dermally with labeled pesticide. Doses, in mg/cm2, are applied to the shaven skin of the back as the use product, diluted with water if necessary. The application site is protected with a nonocclusive device. Four rats per dose are exposed for 0.5, 1, 2, 4, 10, or 24 hrs. Samples collected are soap and water wash, skin at the application site, blood, total urine and feces, carcass, and selected tissues. Mass balance calculations include determination of pesticide that can be removed with soap and water, pesticide bound on or in the skin, total pesticide absorbed with time, blood concentrations with time, pesticide accumulation in target tissues, and pesticide excreted.

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