EAWAG-SOIL package

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General Description

“EAWAG-SOIL” package contains pathway information from soil degradation studies, stored in a biotransformation reaction scheme in the object pathway. This information is extracted from pesticide registration dossiers (draft assessment reports, DAR) made publically available through the European Food Safety Authority (EFSA). The package also contains information on different experimental conditions that are stored in the object scenario. Compounds in the pathway are associated with a given scenario if they have been observed under the specific experimental conditions. If available, a biotransformation half-life (DT50) value is additionally associated with a given compound in the pathway and a specific scenario.

enviPath conventions to store EAWAG-SOIL data

Scenario name

The scenario name is generated using the author name and year of the study, “Author name, Year” and in some cases also the study name, “Study name, Author name, Year”.

Scenario description

A small description of the scenario with information concerning the date of the submission of the DAR soil (date of the dossier on the first page).

Soil origin

Information on the soil source, typically indicating the place where the sample was collected - city, canton or state and country.

Soil description

Information on soil texture classification and percentage of sand, clay and silt in the soil. The soil texture is a qualitative classification used for determination of soil classes based on their physical texture.

Soil texture classification system

Information on the soil texture classification system used to derived the soil texture given in “soil description”. Information from the USDA classification system is preferred if information from more than one classification system is available.

Redox conditions

All data stored in the package EAWAG-SOIL are from aerobic studies. Data from anaerobic-aerobic and anaerobic studies are not included.

Acidity, pH

pH at which the study was conducted. For cases where pH was determined in different soil solutions (i.e., H2O, KCl, CaCl2), only one value is stored using the following order of preference: CaCl2 > KCl > H2O. If available, the pH range of the experiment is stored.

Temperature

Temperature at which the experiment was performed in °C.

Water storage capacity

Information on how much water the soil can hold under a given “condition”, in g/100g soil or mass-%. The field “condition” indicates under which conditions the water storage capacity was measured (i.e., “(maximum) water holding capacity”, pF 2, 1/3 bar etc.).

Experimental humidity

Indicate in % at what percentage of the “water storage capacity” the experiment was actually run.

Organic content

Information on soil organic matter (OM) or organic carbon (OC) content in mass-%. If both values were available in the DAR, the value that has actually been measured (and not derived from the respective other value) is stored.

Cation exchange capacity, CEC

Information on the number of exchangeable cations that a soil is capable of holding per dry weight at a given pH value and available for exchange with the soil water solution, measured in milliequivalent of hydrogen per 100g of dry soil.

Bulk density

Weight of dry soil in a given soil volume in g/cm3.

Biomass

Biomass is the part of soil organic matter that is made up by living organisms, mostly bacteria and fungi. Data is stored in µg of carbon/g soil.

Compound names

Compounds are named according to the DAR key (“identifier”) used in the dossier for each compound. This may lead to different compounds having the same name (e.g., Mxy). Names are therefore not unique in the EAWAG-SOIL package.

DT50 values

The DT50 value (50% dissipation time) is the time required for 50% of the initial concentration of the compound under study to dissipate (in days). DT50 values do not per se assume a specific kinetic model. Only DT50 values measured at the original temperature of the experiment are stored. When several DT50 values are given for the same set of data (e.g., original submission, re-calculated by a “reviewing committee”, different kinetic models etc.), only the value that shows the best quality is stored (e.g., based on quality of fit, R2 values, comments in the text etc.).

Additional information on the selected DT50 value stored:

  • whether or not it is derived from a first-order kinetic model
  • a comment about the reason for selecting that specific value (if needed)

DT50 values should always be available for the parent pesticides. In some cases, they have also been measured for major transformation products, and hence are also stored.

Spike concentrations/Spike compounds

The molecular formula of the spike compound, including isotopic information, using SMILES strings. For indicating the specific position of the 14C-label, the following rules were followed:

  • If a specific position is indicated in the structures drawn in the DAR, the structure is stored with the label at that specific position
  • If the radioactivity “mark” (in general, star symbol) is in the middle of the aromatic ring or if the compound is given as [U14C]-compound, then the structure is stored with the 14C-label in all C atoms in the aromatic ring.