Assessment and Significance of Sediment-Associated Oil and Grease in Aquatic Environments.

A review of the literature suggests that the term oil and grease, as used in descriptive and regulatory context for dredged material disposal, is a broadly based term defined by the methodology used in its determination. Oil and grease contains numerous natural and petroleum derived hydrocarbons, plus fats, oil, and waxes of both natural and anthropogenic origin. Also included in oil and grease are trace quantities of fat-soluble materials such as DDT and PCB. Elemental sulfur is a contaminant often included in oil and grease determinations by virtue of its solubility in some organic solvents. Although some oil and grease fractions are readily degraded by microbiological action, many petroleum hydrocarbons are resistant to decomposition. Little is known concerning the effects of sediment-associated oil and grease on organisms and ecosystems, although in the case of certain oil spills it is known that toxic oily residues can be retained over periods of years in sediments with little abatement of their toxic properties.