Pollution in Terrestrial and Aquatic Sediment
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article.
Pollution problems in aquatic sediments and on land can be quite varied—from the widespread contamination of a coastal bay receiving untreated urban or industrial discharge to the local leakage from underground petroleum tanks or pipelines. Such problems are related to the range of sediment and soil in which they occur. Sediments and soil particles can be carriers, receptors, and sources for contaminants. The effectiveness of these roles is largely related to their adsorptive capacity and is governed mainly by particle size, mineralogy, and organic matter as well as site-specific geochemical conditions. Sustainable use of land and marine areas requires a source-to-sink system perspective in order to prescribe remedial actions. Measures can focus on preventing release from the source, spreading along selective pathways, stabilization, and isolation to protect the receptor. Therefore, many traditional scientific goals, such as provenance (sediment source) identification, the interpretation of sediment transport modes and directions, and post-depositional (diagenetic) changes, are applicable and complementary tools to increase predictability between sampled sites.
The carrier function of aquatic sediments is emphasized when contaminates are transported to the site of accumulation. Ground pollution in terrestrial settings, on the other hand, is often due to more local sources. Nevertheless, retention and ecological exposure is dependent on the particle-solute interactions. The stratigraphic architecture of ground environments can also decisively influence the spread of contaminants, contrasting with the largely two-dimensional redistribution of eroded aquatic sediments. Diffuse pollution sources, including agriculture, urban, transportation, and industrial sources, contribute significantly to overall environmental stress. Quantitative modeling of contaminant fluxes is increasingly possible with database availability, but relative risk ranking is still a necessary simplification in many decision-support evaluations due to the complexity of sediment and ground environments.