Properties of organic compounds that correlate with time-dependent reductions of availability in soil

A study was conducted of the properties that may affect the availability of organic compounds that persist in soil for a range of times. Sequestration, a time-dependent reduction in availability, was measured by bacterial mineralization, earthworm uptake, and solvent extraction. The 35 compounds tested including a phenoxyacetic acid herbicide, alkyl alcohols, a basic herbicide, phenylurea compounds, a fatty acid, linear alkanes, polycyclic aromatic hydrocarbons, and a volatile aromatic compound. All compounds became sequestered with time except for acetic acid and di(2-ethylhexyl) phthalate. Although a range of classes of chemical compounds became sequestered, both highly hydrophilic and hydrophobic compounds did not become sequestered. This lack of time-dependent reduction in availability may have been due to properties of the compound or the methods of assaying sequestration. The results of assays of mineralization, uptake, and extraction did not always agree; however, chemical assays were found that paralleled the loss in availability to bacteria and a species of earthworm.;An attempt was made to modify the Ames Salmonella mutagenicity assay to assess the availability of soil contaminants in a solid-phase assay. Because the Salmonella strains used in the assay did not grow in the test soil, the attempt was not successful.;A Quantitative Structure-Activity Relationship approach was used to correlate sequestration in soil with the properties of 24 organic compounds including pesticides and polycyclic aromatic hydrocarbons. When sequestration was expressed as the difference in the extractability of the compounds aged in soil for 0 and 28 d, the best single predictor (R...