268
v. MiklavCic
the results obtained. Close to the Municipal Museum, which is located in castle,
we found high concentrations of mercury content too (396 ng Hg g-' d.s.),
which agrees with our measurements of mercury in transplanted lichens and
measurements of mercury in air (Gosar et al. 1996). In the centre of the town the
result obtained was quite high (321 ng Hg g-' d.s.), which confirms the influence
of the ventilation shaft located in the town centre. In the Pront area, where native
mercury and cinnabar ore are present in the surface soil, we found 275 ng Hg g-'
of dry sample. We found that other ventilation shaft does not have a great
influence. Determinations of mercury in carrot from this part of town (locations
9 and 10 in Fig. 2) did not show such high concentrations (78163 ng Hg g-' d.s.). The lowest mercury content (60 ng Hg g-' d.s.) in carrot
was found far away from the smelting plant and ventilating shafts. It is evident
that there was no source of Hg, nearby.
We found beans at only six of the sampling locations. The concentrations of
Hg in beans are 2 to 7 times lower than in carrot. The higest values were
determined at the location close to the smelting plant (18 ng Hg g-' d.s.) and
Pront area (23 ng Hg g-' d.s.). These are quite interesting results, because the
concentration of Hg in carrot from these locations were very different. Probably
the carrot reflects air pollution with Hg and the bean soil pollution. The Hg
contents from other locations were in the interval between 2.0-6.6 ng Hg g-' d.s.
These results confirm the fact that carrot really can bioaccumulate and assimilate
Hg during its growth. Probably it could distinguish between originating in air
and that in soil.
4
Conclusion
If we compare our results obtained with those from the 1970S (Stegnar 1980), we
can see that the smelting plant was really an important source of Hg pollution,
and that the Pront area results reflect the fact that at this site Hg originates from
the geological structure.
Generally, the Hg content in carrot from Idrija town are still very high. The
Slovenian legislation allows on MAC of 100 ng Hg g-' of dry sample and
20 ng Hg g -. of fresh sample. It has been shown that only at two sampling
locations were the concentrations under the MAC. In six locations the values
obtained are higher than 200 ng Hg g -. d.s.
From the results and measurements it is evident that much mercury is still
present in the Idrija town environment in spite of the fact that most mercury
production was ended in 1977. It is evident from trends found in this work that a
longterm programme of environmental monitoring is required. Such a comprehensive survey should be carried out at intervals to follow declining trends in
mercury levels, not only to safeguard man and the environment, but also to
provide valuable data on the ecological cycle of mercury.
v. MiklavCic
the results obtained. Close to the Municipal Museum, which is located in castle,
we found high concentrations of mercury content too (396 ng Hg g-' d.s.),
which agrees with our measurements of mercury in transplanted lichens and
measurements of mercury in air (Gosar et al. 1996). In the centre of the town the
result obtained was quite high (321 ng Hg g-' d.s.), which confirms the influence
of the ventilation shaft located in the town centre. In the Pront area, where native
mercury and cinnabar ore are present in the surface soil, we found 275 ng Hg g-'
of dry sample. We found that other ventilation shaft does not have a great
influence. Determinations of mercury in carrot from this part of town (locations
9 and 10 in Fig. 2) did not show such high concentrations (78163 ng Hg g-' d.s.). The lowest mercury content (60 ng Hg g-' d.s.) in carrot
was found far away from the smelting plant and ventilating shafts. It is evident
that there was no source of Hg, nearby.
We found beans at only six of the sampling locations. The concentrations of
Hg in beans are 2 to 7 times lower than in carrot. The higest values were
determined at the location close to the smelting plant (18 ng Hg g-' d.s.) and
Pront area (23 ng Hg g-' d.s.). These are quite interesting results, because the
concentration of Hg in carrot from these locations were very different. Probably
the carrot reflects air pollution with Hg and the bean soil pollution. The Hg
contents from other locations were in the interval between 2.0-6.6 ng Hg g-' d.s.
These results confirm the fact that carrot really can bioaccumulate and assimilate
Hg during its growth. Probably it could distinguish between originating in air
and that in soil.
4
Conclusion
If we compare our results obtained with those from the 1970S (Stegnar 1980), we
can see that the smelting plant was really an important source of Hg pollution,
and that the Pront area results reflect the fact that at this site Hg originates from
the geological structure.
Generally, the Hg content in carrot from Idrija town are still very high. The
Slovenian legislation allows on MAC of 100 ng Hg g-' of dry sample and
20 ng Hg g -. of fresh sample. It has been shown that only at two sampling
locations were the concentrations under the MAC. In six locations the values
obtained are higher than 200 ng Hg g -. d.s.
From the results and measurements it is evident that much mercury is still
present in the Idrija town environment in spite of the fact that most mercury
production was ended in 1977. It is evident from trends found in this work that a
longterm programme of environmental monitoring is required. Such a comprehensive survey should be carried out at intervals to follow declining trends in
mercury levels, not only to safeguard man and the environment, but also to
provide valuable data on the ecological cycle of mercury.