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1.
Appl Radiat Isot ; 66(11): 1582-7, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18513979

ABSTRACT

This paper aims to quantify the soil sampling uncertainty arising from the short-range spatial variability of elemental concentrations in the topsoils of agricultural, semi-natural, and contaminated environments. For the agricultural site, the relative standard sampling uncertainty ranges between 1% and 5.5%. For the semi-natural area, the sampling uncertainties are 2-4 times larger than in the agricultural area. The contaminated site exhibited significant short-range spatial variability in elemental composition, which resulted in sampling uncertainties of 20-30%.


Subject(s)
Algorithms , Data Interpretation, Statistical , Models, Statistical , Radiation Monitoring/methods , Soil Pollutants, Radioactive/analysis , Computer Simulation , Italy , Radiation Dosage , Reproducibility of Results , Sample Size , Sensitivity and Specificity , Specimen Handling/methods
2.
Appl Radiat Isot ; 66(11): 1691-4, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18514534

ABSTRACT

The National Environmental Protection Agency of Italy (APAT) performed a soil sampling intercomparison, inviting 14 regional agencies to test their own soil sampling strategies. The intercomparison was carried out at a reference site, previously characterised for metal mass fraction distribution. A wide range of sampling strategies, in terms of sampling patterns, type and number of samples collected, were used to assess the mean mass fraction values of some selected elements. The different strategies led in general to acceptable bias values (D) less than 2sigma, calculated according to ISO 13258. Sampling on arable land was relatively easy, with comparable results between different sampling strategies.


Subject(s)
Data Interpretation, Statistical , Radiation Monitoring/methods , Soil Pollutants, Radioactive/analysis , Italy , Radiation Dosage , Radiation Monitoring/standards , Reproducibility of Results , Sample Size , Sensitivity and Specificity
3.
Appl Radiat Isot ; 66(11): 1595-8, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18501618

ABSTRACT

This paper reports one practical method to estimate the measurement uncertainty including sampling, derived by the approach implemented by Ramsey for soil investigations. The methodology has been applied to estimate the measurements uncertainty (sampling and analyses) of (137)Cs activity concentration (Bq kg(-1)) and total carbon content (%) in suspended particle sampling in a freshwater ecosystem. Uncertainty estimates for between locations, sampling and analysis components have been evaluated. For the considered measurands, the relative expanded measurement uncertainties are 12.3% for (137)Cs and 4.5% for total carbon. For (137)Cs, the measurement (sampling+analysis) variance gives the major contribution to the total variance, while for total carbon the spatial variance is the dominant contributor to the total variance. The limitations and advantages of this basic method are discussed.


Subject(s)
Data Interpretation, Statistical , Fresh Water/analysis , Government Regulation , Radiation Monitoring/instrumentation , Radioisotopes/analysis , Specimen Handling/instrumentation , Water Pollutants, Radioactive/analysis , Algorithms , Environmental Exposure/analysis , Fresh Water/chemistry , Italy , Radiation Monitoring/methods , Radiation Protection/methods , Reproducibility of Results , Sensitivity and Specificity , Specimen Handling/methods , Ultrafiltration/instrumentation , Ultrafiltration/methods
4.
Appl Radiat Isot ; 66(11): 1588-91, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18511285

ABSTRACT

In the frame of the international SOILSAMP project, funded and coordinated by the Italian Environmental Protection Agency, an agricultural area was established as a reference site suitable for performing soil sampling inter-comparison exercises. The reference site was characterized for trace element content in soil, in terms of the spatial and temporal variability of their mass fraction. Considering that the behaviour of long-lived radionuclides in soil can be expected to be similar to that of some stable trace elements and that the distribution of these trace elements in soil can simulate the distribution of radionuclides, the reference site characterised in term of trace elements, can be also used to compare the soil sampling strategies developed for radionuclide investigations.


Subject(s)
Data Interpretation, Statistical , Radiation Monitoring/methods , Radiation Monitoring/standards , Soil Pollutants, Radioactive/analysis , Soil Pollutants, Radioactive/standards , Soil/standards , Italy , Radiation Dosage , Reference Values , Reproducibility of Results , Sample Size , Sensitivity and Specificity , Specimen Handling/methods
5.
Chemosphere ; 70(5): 745-52, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17888487

ABSTRACT

In the frame of the international SOILSAMP project, funded and coordinated by the National Environmental Protection Agency of Italy (APAT), uncertainties due to field soil sampling were assessed. Three different sampling devices were applied in an agricultural area using the same sampling protocol. Cr, Sc and Zn mass fractions in the collected soil samples were measured by k(0)-instrumental neutron activation analysis (k(0)-INAA). For each element-device combination the experimental variograms were calculated using geostatistical tools. The variogram parameters were used to estimate the standard uncertainty arising from sampling. The sampling component represents the dominant contribution of the measurement uncertainty with a sampling uncertainty to measurement uncertainty ratio ranging between 0.6 and 0.9. The approach based on the use of variogram parameters leads to uncertainty values of the sampling component in agreement with those estimated by replicate sampling approach.


Subject(s)
Environmental Monitoring/methods , Soil Pollutants/analysis , Agriculture , Calibration , Chromium/analysis , Environmental Monitoring/statistics & numerical data , Italy , Quality Control , Reproducibility of Results , Scandium/analysis , Sensitivity and Specificity , Specimen Handling/methods , Uncertainty , Zinc/analysis
6.
Ann Ist Super Sanita ; 41(3): 343-52, 2005.
Article in Italian | MEDLINE | ID: mdl-16552125

ABSTRACT

Metals and radionuclides in water systems can be easily adsorbed on suspended matter and, finally, they could eventually accumulate in the aquatic environment. The assessment of the health of a water body needs also sampling of the suspended matter fraction. In this paper sampling systems to characterise contaminants associated with the suspended matter fraction are described, with a particular attention to the collection and preservation of samples. Sampling must be representative, to obtain reliable conclusions. In this context it is stressed the importance of the evaluation of the sampling uncertainty, which contributes to a large extent to the total uncertainty.


Subject(s)
Environmental Monitoring/methods , Fresh Water/analysis , Geologic Sediments , Specimen Handling/methods , Water Pollution/analysis , Adsorption , Automation , Environmental Monitoring/instrumentation , Filtration , Geologic Sediments/chemistry , Inorganic Chemicals/analysis , Italy , Organic Chemicals/analysis , Particle Size , Specimen Handling/instrumentation , Suspensions , Water/analysis , Water/standards , Water Pollution/prevention & control
7.
Environ Pollut ; 127(1): 131-5, 2004.
Article in English | MEDLINE | ID: mdl-14554003

ABSTRACT

The paper reports a methodology adopted to face problems related to quality assurance in soil sampling. The SOILSAMP project, funded by the Environmental Protection Agency of Italy (APAT), is aimed at (i) establishing protocols for soil sampling in different environments; (ii) assessing uncertainties associated with different soil sampling methods in order to select the "fit-for-purpose" method; (iii) qualifying, in term of trace elements spatial variability, a reference site for national and international inter-comparison exercises. Preliminary results and considerations are illustrated.


Subject(s)
Environmental Monitoring/methods , Soil Pollutants/analysis , Environmental Monitoring/statistics & numerical data , Quality Control , Sensitivity and Specificity , Specimen Handling/methods
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