Studies should focus on health effects of the oil spill rather than solely on the health effects of the oil. Previous epidemiologic studies of oil spills have primarily focused on acute physical effects and psychological sequelae (10–14). Increasing evidence, largely from the Prestige oil spill, suggests that clean-up workers may also experience long-term respiratory effects and chromosomal damage (7–9). Studies in the Gulf of Mexico should investigate acute symptoms reported previously as well as delayed conditions, such as cancer. Leukemia, multiple myeloma, and melanoma are of particular interest on the basis of evidence from occupational studies of petrochemical workers (15–16). Evidence of genotoxicity and chromosomal damage from the Prestige spill (7) demonstrates the importance of examining biomarkers, such as genetic, epigenetic, immune, and inflammatory alterations, because the latent period of some diseases, including cancer, is long. Mental health and domestic violence will also be important to investigate, given that the oil spill disrupted the region's economy.