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Statistical methods for environmental pollution monitoring

Description: The application of statistics to environmental pollution monitoring studies requires a knowledge of statistical analysis methods particularly well suited to pollution data. This book fills that need by providing sampling plans, statistical tests, parameter estimation procedure techniques, and references to pertinent publications. Most of the statistical techniques are relatively simple, and examples, exercises, and case studies are provided to illustrate procedures. The book is logically divide… more
Date: 1987~
Creator: Gilbert, R. O.
Item Type: Refine your search to only Book
Partner: UNT Libraries Government Documents Department
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TRAN-STAT, Issue No. 1, September 1977. Topics discussed: quantitative aspects of Pu field studies

Description: The purpose of TRAN-STAT is to stimulate thinking about how better use can be made of statistics in the design and analysis of environmental transuranic studies. Topics discussed include current statistical studies on the quantitative aspects of plutonium field studies, appropriate data summaries for transuranic studies, and new statistical references of interest.
Date: September 1, 1977
Creator: Gilbert, R.O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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TRAN-STAT, Issue No. 2, November 1977. Topics discussed: some statistical aspects in the evaluation of environmental transuranic contamination for possible remedial action

Description: Some statistical aspects surrounding the question of whether an area contaminated to some extent by transuranium elements requires some type of remedial action to guard against a possible health hazard to man are discussed. It is assumed that an upper limit on the level of contamination in soil has been set and that the main problem is to collect environmental soil sampled in order to make a decision whether the area being samples does exceed the agreed upon limits. Methods discussed involve th… more
Date: November 1, 1977
Creator: Gilbert, R.O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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TRAN-STAT, Issue No. 3, January 1978. Topics discussed: some statistical aspects of compositing field samples

Description: Some statistical aspects of compositing field samples of soils for determining the content of Pu are discussed. Some of the potential problems involved in pooling samples are reviewed. This is followed by more detailed discussions and examples of compositing designs, adequacy of mixing, statistical models and their role in compositing, and related topics.
Date: January 1, 1978
Creator: Gilbert, R.O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Recommendations concerning the computation and reporting of counting statistics for the Nevada Applied Ecology Group

Description: Recommendations are made concerning the computation and reporting of count statistics relative to the analysis of environmental samples for plutonium, uranium, and other radionuclides. Computational formulas are given for determining whether contamination above background level exists in the sample; computing confidence intervals about the true net counting or disintegration rate of the sample; determining the minimum true net disintegration rate that will be detected most of the time; and repo… more
Date: September 1, 1975
Creator: Gilbert, R.O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Updated estimates of /sup 239/ /sup 240/Pu + /sup 241/Am inventory, spatial pattern, and soil tonnage for removal at Nuclear Site-201, NTS

Description: Updated estimates of /sup 239/ /sup 240/Pu + /sup 241/Am inventory and spatial pattern in surface soil are given for Nuclear Site (NS)-201 in Area 18 of the Nevada Test Site (NTS). These new estimates are based on 712 /sup 241/Am soil concentrations including 185 data values not previously available. Estimates were obtained using essentially the same Kriging techniques and the estimated average /sup 239/ /sup 240/Pu to /sup 241/Am ratio of 7.5 used by Simpson and Gilbert (1980) to obtain previo… more
Date: April 1, 1982
Creator: Simpson, J. C. & Gilbert, R. O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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TRANS-STAT: statistics for environmental studies, Number 16. Extreme value statistics applied to environmental radionuclide studies: Chapters 7 and 8

Description: The commonly used procedure for estimating the Extreme Value distribution of a sequence of measurements implicitly assumes the samples are from a stationary random process. This ignores the well known systematic and cyclic trends that typically occur. Ignoring these trends tends to overestimate the magnitude of the extremes and their associated statistics. This chapter has presented a procedure for including such trends within the parameter estimation algorithm. The result is a better estimate … more
Date: August 1, 1981
Creator: Gilbert, R.O. & Kinnison, R.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Discrepancies in estimates of plutonium levels in soils by different analytical methodologies

Description: A statistically significant discrepancy was found in estimates of plutonium concentrations in a data set of 23 samples where plutonium has been estimated by both Pu/Am ratios and by direct plutonium analysis. Plutonium concentrations derived from Pu/Am ratios average 13% higher than concentrations obtained from chemical analysis. A possible explanation is a change in /sup 241/Am Ge(Li) methodology between the two relevant data sets.
Date: January 1980
Creator: Kinnison, R. R. & Gilbert, R. O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Estimates of amounts of soil removal for clean-up of transuranics at NAEG offsite safety-shot sites

Description: Rough estimates are given for the amount of soil removal necessary to decontaminate five representative safety-shot areas. In order to decontaminate to levels of less than 160 pCi /sup 239/Pu per gram of surface soil, it is estimated that over one-half million tons of soil would have to be removed from the five areas. This is a preliminary estimate based on summary data and concentration contour maps readily available in NAEG publications. More accurate estimates could be obtained by applying K… more
Date: January 1, 1980
Creator: Kinnison, R.R. & Gilbert, R.O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Statistical analyses of in-situ and soil-sample measurements for radionuclides in surface soil near the 116-K-2 trench

Description: Radiation detection surveys are used at the US Department of Energy's Hanford Reservation near Richland, Washington, to determine areas that need posting as radiation zones or to measure dose rates in the field. The relationship between measurements made by Sodium Iodide (NaI) detectors mounted on the mobile Road Monitor vehicle and those made by hand-held GM P-11 probes and Micro-R meters are of particular interest because the Road Monitor can survey land areas in much less time than hand… more
Date: September 1, 1988
Creator: Gilbert, R. O. & Klover, W. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

An approach for testing attainment of soil background standards at Superfund sites

Description: After the soil at a Superfund site has been remediated it is necessary to determine if the remediation effort has been successful. This determination involves comparing concentrations in soil at the remediated site with cleanup standards. The cleanup standard may be based on technological capabilities a risk assessment, or site-specific background concentrations. In this paper we discuss an approach for using two complementary nonparametric tests, the Wilcoxon Rank Sum (WRS) test and the Quanti… more
Date: August 1, 1990
Creator: Gilbert, R. O. & Simpson, J. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Environmental restoration and statistics: Issues and needs

Description: Statisticians have a vital role to play in environmental restoration (ER) activities. One facet of that role is to point out where additional work is needed to develop statistical sampling plans and data analyses that meet the needs of ER. This paper is an attempt to show where statistics fits into the ER process. The statistician, as member of the ER planning team, works collaboratively with the team to develop the site characterization sampling design, so that data of the quality and quantity… more
Date: October 1, 1991
Creator: Gilbert, R.O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Statistical evaluation of cleanup: How should it be done?

Description: This paper discusses statistical issues that must be addressed when conducting statistical tests for the purpose of evaluating if a site has been remediated to guideline values or standards. The importance of using the Data Quality Objectives (DQO) process to plan and design the sampling plan is emphasized. Other topics discussed are: (1) accounting for the uncertainty of cleanup standards when conducting statistical tests, (2) determining the number of samples and measurements needed to attain… more
Date: February 1, 1993
Creator: Gilbert, R. O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Americium-241 in surface soil associated with the Hanford site and vicinity

Description: Various kinds of surface soil samples were collected and analyzed for Americium-241 (/sup 241/Am) to examine the feasibility of improving soil sample data for the Hanford Surface Environmental Surveillance Program. Results do not indicate that a major improvement would occur if procedures were changed from the current practices. Conclusions from this study are somewhat tempered by the very low levels of /sup 241/Am (< 0.10 pCi/g dry weight) detected in surface soil samples and by the fact that … more
Date: May 1, 1981
Creator: Price, K. R.; Gilbert, R. O. & Gano, K. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Discussion of the paper ``the use of conditional simulation in nuclear waste site performance assessment,`` by Carol A. Gotway

Description: First, we applaud Dr. Gotway for seeking via her paper to expose a wider audience of statisticians to the many interesting and challenging modeling and statistical problems in the environmental area. This well-written paper effective explains the WIPP and the context of the analysis. Dr. Gotway`s paper describes a geostatistical conditional simulation approach combined with deterministic modeling to estimate the cumulative distribution function (cdf) of groundwater travel time (GWTT), informati… more
Date: August 1, 1993
Creator: Gilbert, R. O. & Doctor, P. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ratio estimation techniques in the analysis of environmental radionuclide data

Description: Ratios play a prominent role in the analysis of environmental transuranic data. The mathematical assumptions underlying the use of ratios are presented. The properties of seven different estimators of an average ratio and their standard errors are discussed with respect to their applicability to transuranic field studies. The behavior of these estimators, their standard errors, and confidence intervals are compared for three representative sets of data from safety-shot sites at the Nevada Test … more
Date: January 1, 1977
Creator: Doctor, P G & Gilbert, R O
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Some design aspects of transuranic field studies

Description: In this paper we discuss some design aspects of transuranic field studies. Some of the principal steps in the design of such studies are given and illustrated using examples. This is followed by a review of sampling designs that have been used at nuclear detonation and safety-shot sites on the Nevada Test Site and elsewhere for estimating spatial pattern and total amounts in soil. Some design aspects of ecosystemtype transuranic studies for estimating total amounts as well as movement of transu… more
Date: December 1, 1976
Creator: Gilbert, R O & Eberhardt, L L
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Statistical analysis of Pu in soil at NTS: some results (an outline)

Description: From NAEG plutonium environmental studies program meeting; Las Vegas, Nevada, USA (2 Oct 1973). The inventory of /sup 239/Pu and /sup 240/Pu at various depths in surface soil samples collected from various locations at the Nevada Test Site was determined. Isopleths were constructed for use in stratified random sampling to estimate surface inventory. Gamma scans for /sup 241/Am were made on all soil samples for comparison with the determinations of / sup 239/Pu and /sup 240/Pu made using wet che… more
Date: January 1, 1973
Creator: Gilbert, R.O. & Eberhardt, L.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Comparing statistical tests for detecting soil contamination greater than background

Description: The Washington State Department of Ecology (WSDE) recently issued a report that provides guidance on statistical issues regarding investigation and cleanup of soil and groundwater contamination under the Model Toxics Control Act Cleanup Regulation. Included in the report are procedures for determining a background-based cleanup standard and for conducting a 3-step statistical test procedure to decide if a site is contaminated greater than the background standard. The guidance specifies that the… more
Date: December 1, 1993
Creator: Hardin, J. W. & Gilbert, R. O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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