310
A. Gnamus and M. Horvat
and kidney represent organs having a leading role in metabolic modifications
and transformations of various Hg species entering the animal body and their
enhanced Hg concentrations were expected. It is important to note that T -Hg
concentrations in kidney cortex of exposed roe deer reached up to 75 mg Hg/g
f.w. and were an order of magnitude higher than Hg values in liver. It is
expected that the processes of partial conversion of Me-Hg compounds, i.e.
demethylation and elimination of Hg are carried out in these two organs. On
the other hand, depending on the metabolic rate and concentrations and
species of Hg present, they may transfer some Hg to other organs, causing
potential adverse effects in cytogenetic, physiological, neurological or metabolic
processes. Considering high Hg concentrations in fur, a possible mode of Hg
elimination through the seasonal replacement of fur is suggested. Thus, fur may
have an important role in long-term balancing of the Hg body burdens in areas
contaminated by Hg. Considering its high Hg content, the possible contribution
of airborne Hg deposition to the fur surface should be taken into account and
its role and size in the overall fur Hg concentrations elucidated. It is well
known that elemental Hgo, which is the most abundant Hg form in Idrija air,
does not accumulate in fur related tissues, e.g. hair (Chatt and Katz 1988), but
since the fur of the animals was not washed prior to analysis, the possible
contribution of surface contamination to the T -Hg fur concentrations must not
be neglected.
4.7
Is It Possible to Explain the Observed Age
and Sex-Related Hg Concentration Fluctuations?
The relationship between Hg content in tissues and the age of the organism was
studied in roe deer. If roe deer are to be considered reliable bioindicators of
environmental Hg fluctuations, the alterations of the Hg distribution patterns
due to age and sex should be studied, beside the response to Hg distribution from
the spatial contamination pattern. Positively correlated mercury values in roe
deer and environmental samples with distance from the Hg pollution source were
already established (see Table 4 and Fig. 4; Gnamus et al. 1995, 1996). Good
agreement between Hg concentrations in various roe deer tissues and the
environmental data was shown.
To minimize interferences with the spatial contamination pattern in the
polluted Idrija area, the age and mercury content correlations of the animals
within each of the contamination zones (Zones A, B) or even within each of the
sampling polygons (1-1, 1-2,) should be compared (see Table 3 and Fig. 3a,b). In
this way, the anomalies in Hg pollution between the sampling areas could be
greatly reduced. However, a relatively good age-related accumulation pattern was
observed in control animals only.
We must be aware of the fact that the number of roe deer (n = 20) examined
so far is relatively small and that deviations from the expected trends might be
related to the individual differences between particular specimens. In the distinctively contaminated Idrija area the concentrations of mercury in the limited
A. Gnamus and M. Horvat
and kidney represent organs having a leading role in metabolic modifications
and transformations of various Hg species entering the animal body and their
enhanced Hg concentrations were expected. It is important to note that T -Hg
concentrations in kidney cortex of exposed roe deer reached up to 75 mg Hg/g
f.w. and were an order of magnitude higher than Hg values in liver. It is
expected that the processes of partial conversion of Me-Hg compounds, i.e.
demethylation and elimination of Hg are carried out in these two organs. On
the other hand, depending on the metabolic rate and concentrations and
species of Hg present, they may transfer some Hg to other organs, causing
potential adverse effects in cytogenetic, physiological, neurological or metabolic
processes. Considering high Hg concentrations in fur, a possible mode of Hg
elimination through the seasonal replacement of fur is suggested. Thus, fur may
have an important role in long-term balancing of the Hg body burdens in areas
contaminated by Hg. Considering its high Hg content, the possible contribution
of airborne Hg deposition to the fur surface should be taken into account and
its role and size in the overall fur Hg concentrations elucidated. It is well
known that elemental Hgo, which is the most abundant Hg form in Idrija air,
does not accumulate in fur related tissues, e.g. hair (Chatt and Katz 1988), but
since the fur of the animals was not washed prior to analysis, the possible
contribution of surface contamination to the T -Hg fur concentrations must not
be neglected.
4.7
Is It Possible to Explain the Observed Age
and Sex-Related Hg Concentration Fluctuations?
The relationship between Hg content in tissues and the age of the organism was
studied in roe deer. If roe deer are to be considered reliable bioindicators of
environmental Hg fluctuations, the alterations of the Hg distribution patterns
due to age and sex should be studied, beside the response to Hg distribution from
the spatial contamination pattern. Positively correlated mercury values in roe
deer and environmental samples with distance from the Hg pollution source were
already established (see Table 4 and Fig. 4; Gnamus et al. 1995, 1996). Good
agreement between Hg concentrations in various roe deer tissues and the
environmental data was shown.
To minimize interferences with the spatial contamination pattern in the
polluted Idrija area, the age and mercury content correlations of the animals
within each of the contamination zones (Zones A, B) or even within each of the
sampling polygons (1-1, 1-2,) should be compared (see Table 3 and Fig. 3a,b). In
this way, the anomalies in Hg pollution between the sampling areas could be
greatly reduced. However, a relatively good age-related accumulation pattern was
observed in control animals only.
We must be aware of the fact that the number of roe deer (n = 20) examined
so far is relatively small and that deviations from the expected trends might be
related to the individual differences between particular specimens. In the distinctively contaminated Idrija area the concentrations of mercury in the limited