Mercury in Terrestrial Food Webs of the Idrija Mining Area
303
the sampling microlocation and of the plant specimen, individual physiological
demands and characteristics, etc.) it is advisable for biomonitoring to use a
multispecies composite mixed plant samples of a defined individual species
percentage composition. Biomonitoring using such composite samples instead of
single plant species samples is much more representative for the contaminated
area examined. Moreover, a higher representativeness as concern Hg concentrations can be obtained, since the variety of over 40 plant species usually
represent a very large portion of a certain area's forest vegetation cover.
However, the main concern of the terrestrial vegetation mercury content in this
article was related to the Hg transfer from the soil and airborne Hg
contamination into food chains. The contamination of vegetation due to aerial
Hg deposition and root uptake results in adsorption/absorption of the metal on/
in plant leaves, by which the extent of Hg accumulation in the first link of the
terrestrial food chain is achieved. Thus, Hg accumulated in terrestrial vegetation
is transferred to the primary consumer's link (herbivorous animals) in terrestrial
food webs, in this study represented by roe deer.
Mercury concentrations in roe deer tissues are strongly dependent on the
chosen tissue (Table 6). Different T-Hg contents of various animal tissues are
related to their metabolic activity and function, and are frequently relatively high
(see Fig. 4 deviations in Hg values between various roe deer tissues obtained
from each particular sampling area). In this section mercury values for each body
tissue of the particular roe deer from the contamination zones A and B of the
polluted Idrija area are summarized separately according to the order of the Hg
concentrations measured. For all sampling sites an identical order of tissues was
discovered, as presented below. In brackets ranges of Hg concentration values
expressed on f.w. (fresh weight) basis are presented. The approximate overall
concentration ranges of mercury (T -Hg) in all examined tissues and organs of
roe deer from the Idrija district (Zones A and B) follow the order:
kidney (1-75 ~lg/g) » liver (0.1-1.7 ~lg/g) > fur (0.1-1.3 ~lg/g) » pineal gland
(0.02-0.3 ~lg/g) > > masseter muscle «0.15 ~lg/g) > suprarenal gland «0.12 ~lg/
g) > spleen ("-' O.lqlg/g) > lungs ("-' O.qlg I g) > pituitary (0.02 - 0.1 ~lg/g) >
eye sections «0.1 ~lg/g) > sections of the CNS «0.03 ~lg/g).
The concentrations of T -Hg in roe deer tissues from the Idrija mining area
were about 100 times higher than those in the controls. The same principles of
roe deer tissue ranking were used for Me-Hg tissue accumulation also. For most
of the selected roe deer tissues except fur, Me-Hg concentrations in the Idrija
area were within 10 and 100 ng/g f.w., while in fur the average Me-Hg
concentrations were up to 5 times higher than in other tissues and organs. In
brackets, Me-Hg concentration ranges expressed on f.w. basis are presented. The
corresponding sequence of roe deer tissues ranked by descending Me-Hg
concentrations differ from the one obtained for T-Hg tissue values in the Idrija
district and follow the order:
fur (100-500 ng/g) > kidney (10-100 ng/g) > liver (10-70 ng/g) > masseter
muscle (10-60 ng/g) > other tissues incl. endocrine glands, spleen, lungs, eye
sections and sections of CNS (5-15 ng/g).
303
the sampling microlocation and of the plant specimen, individual physiological
demands and characteristics, etc.) it is advisable for biomonitoring to use a
multispecies composite mixed plant samples of a defined individual species
percentage composition. Biomonitoring using such composite samples instead of
single plant species samples is much more representative for the contaminated
area examined. Moreover, a higher representativeness as concern Hg concentrations can be obtained, since the variety of over 40 plant species usually
represent a very large portion of a certain area's forest vegetation cover.
However, the main concern of the terrestrial vegetation mercury content in this
article was related to the Hg transfer from the soil and airborne Hg
contamination into food chains. The contamination of vegetation due to aerial
Hg deposition and root uptake results in adsorption/absorption of the metal on/
in plant leaves, by which the extent of Hg accumulation in the first link of the
terrestrial food chain is achieved. Thus, Hg accumulated in terrestrial vegetation
is transferred to the primary consumer's link (herbivorous animals) in terrestrial
food webs, in this study represented by roe deer.
Mercury concentrations in roe deer tissues are strongly dependent on the
chosen tissue (Table 6). Different T-Hg contents of various animal tissues are
related to their metabolic activity and function, and are frequently relatively high
(see Fig. 4 deviations in Hg values between various roe deer tissues obtained
from each particular sampling area). In this section mercury values for each body
tissue of the particular roe deer from the contamination zones A and B of the
polluted Idrija area are summarized separately according to the order of the Hg
concentrations measured. For all sampling sites an identical order of tissues was
discovered, as presented below. In brackets ranges of Hg concentration values
expressed on f.w. (fresh weight) basis are presented. The approximate overall
concentration ranges of mercury (T -Hg) in all examined tissues and organs of
roe deer from the Idrija district (Zones A and B) follow the order:
kidney (1-75 ~lg/g) » liver (0.1-1.7 ~lg/g) > fur (0.1-1.3 ~lg/g) » pineal gland
(0.02-0.3 ~lg/g) > > masseter muscle «0.15 ~lg/g) > suprarenal gland «0.12 ~lg/
g) > spleen ("-' O.lqlg/g) > lungs ("-' O.qlg I g) > pituitary (0.02 - 0.1 ~lg/g) >
eye sections «0.1 ~lg/g) > sections of the CNS «0.03 ~lg/g).
The concentrations of T -Hg in roe deer tissues from the Idrija mining area
were about 100 times higher than those in the controls. The same principles of
roe deer tissue ranking were used for Me-Hg tissue accumulation also. For most
of the selected roe deer tissues except fur, Me-Hg concentrations in the Idrija
area were within 10 and 100 ng/g f.w., while in fur the average Me-Hg
concentrations were up to 5 times higher than in other tissues and organs. In
brackets, Me-Hg concentration ranges expressed on f.w. basis are presented. The
corresponding sequence of roe deer tissues ranked by descending Me-Hg
concentrations differ from the one obtained for T-Hg tissue values in the Idrija
district and follow the order:
fur (100-500 ng/g) > kidney (10-100 ng/g) > liver (10-70 ng/g) > masseter
muscle (10-60 ng/g) > other tissues incl. endocrine glands, spleen, lungs, eye
sections and sections of CNS (5-15 ng/g).