Performance criteria and characteristics of field screening test methods.
Ashley-K; Song-R; Schlecht-PC
Am Lab 2002 Jun; 34(12):32-39
Field screening test methods are often used in environmental and industrial hygiene applications for the on-site detection and/or measurement of toxic substances. On-site screening tests are carried out in the field in order to estimate the contents of toxic chemicals in environmental matrices, or to estimate human exposure to toxic species, so that overexposures to these substances can be prevented. The goal of screening analysis may not necessarily be to quantitatively determine the level of a particular toxic substance, but rather to assess whether the chemical species of concern is present above or below regulatory or recommended standard values or action levels. Field screening test methods can provide a timely means for assessing exposures, but the validity of such methods is called into question if their performance has not been evaluated or verified. A statistical formalism has been presented that enables the estimation of performance criteria and characteristics of field screening test methods. By implementing appropriate statistical treatments on measurement data with subsequent confirmatory analysis, it becomes possible to evaluate qualitative, semiquantatative, and quantitative field method for their potential use in screening analysis for given analytes of interest. It should therefore be possible to use the results from screening analysis to make defensible decisions concerning potential human exposure to toxic substances. The use of various methods for screening purposed may depend on the intended applications or purposes of the measurements. The discussion here had focused on the use of such measurements for making decisions concerning analyte concentrations above or below a given standard or action level (threshold). The statistical treatment outlined can be applies to virtually any method that yields a numerical value for any analyte of interest, and therefore has general applicability to field screening analysis
Toxic-materials; Measurement-equipment; Screening-methods; Environmental-pollution; Environmental-hazards; Environmental-factors; Statistical-analysis
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Research Tools and Approaches: Exposure Assessment Methods