However, there is still not a full understanding of the long term effects these spills had on wildlife. These events drew attention to the need for toxicological experiments to better understand the impact of oil and the chemicals used to disperse the oil on wildlife species. Of particular interest are the effects on whales as they are air breathing, warm-blooded mammals that nurse their young and can most closely represent humans in the ocean. Whales are important species in food webs, are one of the major bases of ecotourism, are charismatic species that capture the attention of the public at large and can integrate all possible routes of exposure to dispersants in the environment (air, water and food). Consequently, they make excellent models to use for studying the threats and consequences of oil and dispersant exposure. There is very little laboratory-based data regarding the toxicity of these substances in marine mammals. Thus we sought to determine the toxicity of Alaskan oil, dispersants, and chemically dispersed oil in whales. We found that dispersants are cytotoxic and genotoxic to sperm whales but not genotoxic to humpback cells. In addition, we found that oil induced genotoxic effects in whale cells and adding dispersants increased the toxicity of the oil.