At an underwater volcano, evidence of man’s environmental impact

On July 21, 2006, George Kamenov, a geology faculty member at the University of Florida, holds a small sample of a solution containing sediment collected from hydrothermal vents in the ocean depths. Kamenov is among a team of geologists that is the first to observe “anthropogenic influence” in these deep underwater geysers. Examining deposits retrieved from a hydrothermal site in the Mediterranean near Italy, they discovered lead that did not come from the underlying rocks -- nor from any possible natural source in the nearby region or anywhere in Europe. Instead, they traced the pollutant to an Australian lead mine thousands of miles away. It was imported to Europe, added to gasoline, burned by cars and emitted into the air, later finding its way into the ocean and the hydrothermal vent. (Kristen Bartlett/University of Florida)