Mercury Mines in Europe
59
In order to distinguish geogenic and anthropogenic Hg loads in these soils,
Biester et al. (1997) investigated Hg phases by a temperature-controlled-pyrolysis
technique. The results that mercury is preferentially bound to soil organic matter
demonstrate the importance of mercury deposition on the mercury content in
the soil. In spite of the numerous studies performed on the Idrija mine, there are
no available data on the flux values of mercury from the sources present today in
the study area.
3.3
Mercury in the Air over Idrija
During the period of maximum productivity, the concentrations of mercury in
the air ranged between 0.1 and 10 ~lg/m3. The highest values were determined
near the distillation plant (8.5 ~lg/m3), while in the city centre values of the order
of 0.6 ~lg/m3 were measured. In 1991, about 14 years after the end of major
producing activity, the levels of atmospheric mercury ranged between 10 and
500 ng/m 3 .
Of particular interest are the data published by Gosar et al. (1997), obtained
with the Zeeman atomic absorption spectrometer PA-915 of Russian origin, on
September 24th 1994. The spectrometer was mounted in a car and the mercury
concentration was measured every second. The geochemical map of the
mercury distribution is reported in Fig. 5. The highest values of atmospheric
mercury concentrations (4078 ng/m3) were measured near the smelter and close
to the ventilation shaft (2346 ng/m3). Levels above 50 ng/m 3 were found in the
town centre.
A drastic drop in mercury in the air was also observed by Kobal (1994) after
the production of the mine and the smelter had almost halted. The fact that
mercury contents in the air are high is not only due to the influence of mercury
vapour from the above-mentioned sources, but also because of dumps and the
use of smelter slag in the construction of buildings, and because of the presence
in a part of the soil of rocks containing native mercury.
3.4
Mercury in the Soil
Palinkas et al. (1995) report the total mercury concentration measured on 100 soil
samples collected at 56 sampling sites spaced irregularly along the Idrijca valley
and the slopes of the surrounding hills. The maximum value (87.6 mg/kg) was
determined in the mining area and the vicinity of the smelter. The mean value of
mercury concentration in the soil in the studied area was 15.4 mg/kg, with a
minimum concentration value of 0.4 mg/kg.
The distribution of mercury along four vertical profiles suggests a predominant influence of the fallout on the accumulation of the pollutant.
59
In order to distinguish geogenic and anthropogenic Hg loads in these soils,
Biester et al. (1997) investigated Hg phases by a temperature-controlled-pyrolysis
technique. The results that mercury is preferentially bound to soil organic matter
demonstrate the importance of mercury deposition on the mercury content in
the soil. In spite of the numerous studies performed on the Idrija mine, there are
no available data on the flux values of mercury from the sources present today in
the study area.
3.3
Mercury in the Air over Idrija
During the period of maximum productivity, the concentrations of mercury in
the air ranged between 0.1 and 10 ~lg/m3. The highest values were determined
near the distillation plant (8.5 ~lg/m3), while in the city centre values of the order
of 0.6 ~lg/m3 were measured. In 1991, about 14 years after the end of major
producing activity, the levels of atmospheric mercury ranged between 10 and
500 ng/m 3 .
Of particular interest are the data published by Gosar et al. (1997), obtained
with the Zeeman atomic absorption spectrometer PA-915 of Russian origin, on
September 24th 1994. The spectrometer was mounted in a car and the mercury
concentration was measured every second. The geochemical map of the
mercury distribution is reported in Fig. 5. The highest values of atmospheric
mercury concentrations (4078 ng/m3) were measured near the smelter and close
to the ventilation shaft (2346 ng/m3). Levels above 50 ng/m 3 were found in the
town centre.
A drastic drop in mercury in the air was also observed by Kobal (1994) after
the production of the mine and the smelter had almost halted. The fact that
mercury contents in the air are high is not only due to the influence of mercury
vapour from the above-mentioned sources, but also because of dumps and the
use of smelter slag in the construction of buildings, and because of the presence
in a part of the soil of rocks containing native mercury.
3.4
Mercury in the Soil
Palinkas et al. (1995) report the total mercury concentration measured on 100 soil
samples collected at 56 sampling sites spaced irregularly along the Idrijca valley
and the slopes of the surrounding hills. The maximum value (87.6 mg/kg) was
determined in the mining area and the vicinity of the smelter. The mean value of
mercury concentration in the soil in the studied area was 15.4 mg/kg, with a
minimum concentration value of 0.4 mg/kg.
The distribution of mercury along four vertical profiles suggests a predominant influence of the fallout on the accumulation of the pollutant.