| Contents Notes |
The environmental fate and behavior of several toxic organic materials are reviewed in the final report on which this summary is based. This effort has sought to summarize the chemical and physical properties of these materials, and discusses how these properties affect persistence and behavior of toxic chemicals in the soil/water/air systems. In general, the organic carbon content of a soil has the greatest effect on the behavior of hydrophobic toxic organic compounds. The organic compounds sorb strongly to the organic matter in the soil. Several equations have been derived that define water solubility relationships. These are partition coefficients between octanol/water and organic mater/water. Persistence of the toxic organic compounds depends on several environmental factors, including soil organic matter, total precipitation and intensity, temperature, sunlight intensity, and soil texture. Organic chemicals are subject to one or more of seven possible fates: (1) sorption, (2) volatilization, (3) microbial degradation, (4) photodecomposition on the soil surface, (5) translocation to plants, (6) chemical degradation, and (7) leaching to ground water. Some of these fates are directly related to the degree of sorption; i.e., very little of a material that is strongly sorbed will be in solution and available for degradation or movement by the other processes. Some generalities are presented regarding the environmental conditions and chemical/physical properties that affect persistence and mobility; however, the reader should bear in mind that there are always exceptions to the rule. |
