Mercury in the Town of Idrija (Slovenia) After 500 Years of Mining and Smelting
300
M
.€ 250
Ol
I
Ol
.s 200
....
'co
.5
c 150
E
~
C 100
~
c
8 50
Ol
I
o -6
I .. without wind • wind
•
•
•
•
. .
•
3
9
14
Air temperature (0C)
265
21
Fig. 3. Total gaseous mercury concentrations in air as a function of air temperature with or without
influence of wind
These results obtained under different wind conditions point to the considerable influence of the wind on Hg concentrations in air. This indicates that the
main source of Hg emission into the air is most likely the mine's ventilation
shaft, whose effects on Hg concentrations in air is greatly reduced under
favourable wind conditions. Measurements performed in calm weather gave an
average Hg concentration of 135 ng Hg m - 3 of air and those performed in windy
weather an average Hg concentration of only 55 ng Hg m- 3 .
As is evident from Fig. 4, the total Hg content in lichens sampled in situ ranges
from approximately 3 to 23 ~lg Hg g - I d .
s. According to the lowest concentration
of total Hg in lichens, found at the reference location Trebence (0.23 ~lg Hg g-I
d.s.), the results obtained in Idrija were at least 10 times, even 100 times higher.
These results are in accordance with previous data on Hg levels in air there
(Lupsina et a1. 1992). Lichens sampled in areas which are most affected by air
from mine's ventilation shafts show high Hg contents. The highest levels were
recorded in the northern part of Idrija town, probably due to the prevailing
winds in the south-north direction down the valley of the river Idrija, spreading
air-borne Hg, and because of the relief, as in the north of Idrija the valley is
narrowing.
The results confirmed the excessive contamination of air and the environment
in the Idrija region, which is nevertheless not uniformly distributed and is
dependent on many factors, in particular natural and geographic ones. In our
opinion, the most significant role is played by the air flow.
This study also included an attempt at active biomonitoring using transplanted
lichens. We transplanted lichens from the reference location (Trebence) at three
different locations in Idrija town for a period of 5 months (from the beginning of
November 1993 to the end of March 1994). The first location (designated A in
300
M
.€ 250
Ol
I
Ol
.s 200
....
'co
.5
c 150
E
~
C 100
~
c
8 50
Ol
I
o -6
I .. without wind • wind
•
•
•
•
. .
•
3
9
14
Air temperature (0C)
265
21
Fig. 3. Total gaseous mercury concentrations in air as a function of air temperature with or without
influence of wind
These results obtained under different wind conditions point to the considerable influence of the wind on Hg concentrations in air. This indicates that the
main source of Hg emission into the air is most likely the mine's ventilation
shaft, whose effects on Hg concentrations in air is greatly reduced under
favourable wind conditions. Measurements performed in calm weather gave an
average Hg concentration of 135 ng Hg m - 3 of air and those performed in windy
weather an average Hg concentration of only 55 ng Hg m- 3 .
As is evident from Fig. 4, the total Hg content in lichens sampled in situ ranges
from approximately 3 to 23 ~lg Hg g - I d .
s. According to the lowest concentration
of total Hg in lichens, found at the reference location Trebence (0.23 ~lg Hg g-I
d.s.), the results obtained in Idrija were at least 10 times, even 100 times higher.
These results are in accordance with previous data on Hg levels in air there
(Lupsina et a1. 1992). Lichens sampled in areas which are most affected by air
from mine's ventilation shafts show high Hg contents. The highest levels were
recorded in the northern part of Idrija town, probably due to the prevailing
winds in the south-north direction down the valley of the river Idrija, spreading
air-borne Hg, and because of the relief, as in the north of Idrija the valley is
narrowing.
The results confirmed the excessive contamination of air and the environment
in the Idrija region, which is nevertheless not uniformly distributed and is
dependent on many factors, in particular natural and geographic ones. In our
opinion, the most significant role is played by the air flow.
This study also included an attempt at active biomonitoring using transplanted
lichens. We transplanted lichens from the reference location (Trebence) at three
different locations in Idrija town for a period of 5 months (from the beginning of
November 1993 to the end of March 1994). The first location (designated A in