The Open UniversitySkip to content
 

Balancing measurement uncertainty against financial benefits: comparison of in situ and ex situ analysis of contaminated land

Taylor, Paul D.; Ramsey, Michael H. and Potts, Philip J. (2004). Balancing measurement uncertainty against financial benefits: comparison of in situ and ex situ analysis of contaminated land. Environmental Science and Technology, 38(24) pp. 6824–6831.

DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1021/es049739p
Google Scholar: Look up in Google Scholar

Abstract

The uncertainty of measurements taken for the purpose of characterizing contaminated land can subsequently cause decision errors, which can produce significant, financial consequences. Given the site-specific costs, such as those associated with the measurements or with site misclas sification, the important question addressed is "Are the measurements of acceptable quality for that given objective or fit-for-purpose"? It is often considered by investigators that using a standard operating procedure (SOP) with an approved analytical method will give an acceptable level of uncertainty. This is despite evidence that sampling is usually the predominant source of uncertainty, not the chemical analyses, mainly as a result of the contaminant heterogeneity within sampling locations at a site. One in situ and one ex situ measurement technique were used to represent these two contrasting approaches to characterizing a site contaminated with lead in topsoil. The measurement uncertainty, from both sampling and analyses, was estimated for the two techniques, and its fitness-for-purpose was assessed using the innovative optimized contaminated land investigation (OCLI) method. It is objectively demonstrated by the OCLI method that the in situ method (portable X-ray fluorescence) was three times more cost-effective than the ex situ (AAS) method at characterizing a contaminated site, despite generating higher uncertainty on individual measurements.

Item Type: Journal Article
Copyright Holders: 2004 American Chemical Society
ISSN: 0013-936X
Keywords: measurement uncertainty; contaminated land; in situ analysis; financial benefits; portable X-ray fluorescence
Academic Unit/Department: Science > Environment, Earth and Ecosystems
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 5244
Depositing User: Philip Potts
Date Deposited: 02 Aug 2006
Last Modified: 04 Jul 2011 14:34
URI: http://oro.open.ac.uk/id/eprint/5244
Share this page:

Altmetrics

Scopus Citations

Actions (login may be required)

View Item
Report issue / request change

Policies | Disclaimer

© The Open University   + 44 (0)870 333 4340   general-enquiries@open.ac.uk