Environmental Impact of Trace Element Emissions from Geothermal Power Plants

Concentrations of several trace elements were determined in mosses, higher plants and organs of small mammals from a geothermal area in Tuscany (central Italy). Increased deposition of Hg, As, B, and Sb was detected in biological samples collected within a few hundred meters of geothermal power plants. Among the species considered, the moss Hypnum cupressiforme was the most efficient accumulator of trace elements. Contamination levels in a fodder-plant (Hedysarum coronarium) and vegetables grown in the geothermal field did not seem to pose health risks for consumers. However, a statistically significant increase in Hg, B, and As concentrations was found in the kidney and muscle of small mammals living close to geothermal installations. Biological effects of B pollution were detected in two sensitive plant species.