Toxicity enhancement of an aliphatic petrogenic unresolved complex mixture (UCM) by chemical oxidation

The effect of a lubricating oil saturated hydrocarbon feed stock, and its chemical oxidation products, on the feeding rate of mussels (Mytilus edulis), was investigated. The saturated hydrocarbons had no effect, whilst oxidation resulted in an increase in toxicity. The relatively non-toxic nature of the hydrocarbons was attributed to the low aqueous solubility. Oxidation resulted in the formation of products with a greater solubility, which were sufficiently hydrophobic to be narcotic toxicants. The rapid chemical oxidation method may thus provide a “model” for assessing the toxic potential of unresolved complex mixtures (UCMs) in the environment, since it produces compounds similar to those reported to be formed by natural oxidation in the environment and by oxidation of oils in engines, namely carboxylic acids and ketones