GUS. pfm 0.3-7

Usage

GUS(...)
-"GUS"(DT50, Koc, ...)
-"GUS"(chent, degradation_value = "DT50ref", lab_field = "laboratory", redox = "aerobic", sorption_value = "Kfoc", degradation_aggregator = geomean, sorption_aggregator = geomean, ...)
-"print"(x, ..., digits = 1)

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Arguments

...: Included in the generic to allow for further arguments later. Therefore -this also had to be added to the specific methods.
DT50: Half-life of the chemical in soil. Should be a field -half-life according to Gustafson (1989). However, leaching to the sub-soil -can not completely be excluded in field dissipation experiments and Gustafson -did not refer to any normalisation procedure, but says the field study should -be conducted under use conditions.
Koc: The sorption constant normalised to organic carbon. Gustafson -does not mention the nonlinearity of the sorption constant commonly -found and usually described by Freundlich sorption, therefore it is -unclear at which reference concentration the Koc should be observed -(and if the reference concentration would be in soil or in porewater).
chent: If a chent is given with appropriate information present in its -chyaml field, this information is used, with defaults specified below.
degradation_value: Which of the available degradation values should -be used?
lab_field: Should laboratory or field half-lives be used? This -defaults to lab in this implementation, in order to avoid -double-accounting for mobility. If comparability with the original GUS -values given by Gustafson (1989) is desired, non-normalised first-order -field half-lives obtained under actual use conditions should be used.
redox: Aerobic or anaerobic degradation data
sorption_value: Which of the available sorption values should be used? -Defaults to Kfoc as this is what is generally available from the European -pesticide peer review process. These values generally use a reference -concentration of 1 mg/L in porewater, that means they would be expected to -be Koc values at a concentration of 1 mg/L in the water phase.
degradation_aggregator: Function for aggregating half-lives
sorption_aggregator: Function for aggregation Koc values
x: An object of class GUS_result to be printed
digits: The number of digits used in the print method

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Value

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-A list with the DT50 and Koc used as well as the resulting score - of class GUS_result -

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Description

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The groundwater ubiquity score GUS is calculated according to -the following equation -$$GUS = \log_{10} DT50_{soil} (4 - \log_{10} K_{oc})$$

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References

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Gustafson, David I. (1989) Groundwater ubiquity score: a simple -method for assessing pesticide leachability. Environmental -toxicology and chemistry 8(4) 339–57.

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Author