Abstract. Knowledge of the natural emissions of mercury in the Mediterranean basin, which has large cinnabar anomalies, has particular weight as these deposits could be an important source of atmospheric mercury. Data on the degassing rate of mercury from soils sampled both in mineralized areas (Mt. Amiata, Italy and Almaden, Spain) and rural areas are reported. Measurements were carried out "in situ' using a transparent flux chamber and collecting the gaseous mercury on gold collectors. The highest values were observed in Almaden over the roasted cinnabar banks (up to 100 l,g/m'~h) fiom past and present mining activity. In Italian rural areas the values of the volatilization rate of mercury are on the order of few ng/m2h. The degassing rate was observed to be strongly dependent on the ambient temperature and not only seasonal but also daily variations were measured in all the studied areas.

Results from extensive lidar measurements on atmospheric atomic mercury in Italian geothermal fields are reported. A mobile differential absorption lidar system operating on the 254 nm mercury resonance line with a measuring range of about 1 km was used in mineralized as well as non-mineralized areas. Measurements were performed at geothermal power stations and in an unexploited field with natural surface geothermi § manifestations.Atomic mercury concentrations ranging from 2-1000 ng/m were mapped. The high Italian ~eothermal mercury concentrations are in strong contrast to the recent hdar finding of the absence of atomic mercury in Icelandic geothermal fields.

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