Application surrogate values

But also, there are some types of environmental damage attributable to acid pollutant emissions for which no direct or easily applicable surrogate value can be attached. These include ... 

Table 5.12 Surrogate values for mixing/loading/application - formulation type, liquid...

Table 5.14 Specifications for the PHED, taken from the USEPA surrogate tables (PHED, 1998). Unit exposure values were extrapolated to a comparable scenario (2.5-25 kg a.i. handled, based on an application rate of 0.125-0.5 kg a.i./ha and area to be treated of 20-50 ha) ...

A typical example for extended use of the isotope dilution method is the quantification of polychlorinated dioxins. Sixfold and twelvefold labeled dioxins and furans in the required chlorination degrees are used as recovery and surrogate standards during sample preparation and GC-MS analysis, as described in the widely applied EPA 1613 method. The nearly identical compound characteristics during clean-up, the chromatographic process and detection, guarantees most reliable quantitation results based on the sample individual recovery values in one analysis run (see details in the application Section 4.14 on dioxin analysis). 

A common use of the surrogate approach is the application of nationwide accident statistics, on a mileage base, to inferences of the probabilities of accidents occurring on particular routes for which no adequate data exist. However, this neglects the presumably significant differences in the physical, environmental, and behavioral characteristics of some specific routes from nationwide average values of these conditions. 

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