Prepared for: Prince William Sound Regional Citizens ’ Advisory Council

• Main Authors: Mace G. Barron, Mark G. Carls, Jeffrey W. Short, Stanley D. Rice
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2002
• Subjects: Alaska North Slope; north slope; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.485.8370; http://www.arlis.org/docs/vol1/191097893.pdf

Most of the available data on the toxicity and risks of oil and chemically-dispersed oil have been derived from laboratory studies that do not incorporate exposures to the ultraviolet radiation (UV) that occurs in aquatic environments. UV is a component of sunlight, but is not visible to humans. UV contains light energy that can be absorbed by specific components in oil, including PAHs (polycyclic aromatic hydrocarbons). Photoenhanced toxicity has recently been reviewed in an RCAC sponsored study, and is now published in the scientific literature (Barron and Ka’aihue, 2001). The UV that is present in aquatic environments includes UVB (280 to 320 nm) and UVA (320 to 400 nm), where a nanometer (nm; 1 billionth of a meter) is a measure of the specific wavelength of sunlight. Understanding photoenhanced toxicity is important because petroleum and weathered oil is known to be phototoxic, exhibiting a two to greater than 1000 fold increase in toxicity in the presence of UV compared to standard laboratory lighting conditions with fluorescent lights and minimal UV. The photoenhanced toxicity of Alaska North slope crude (ANS) to Alaskan fish species has never been determined, and the potential for photoenhanced toxicity of chemically-dispersed ANS has not been previously evaluated in any species.