Organohalogen concentrations and a gross and histologic ...

Concentration
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
9000
Subadults
8000
7000
6000
5000
4000
3000
2000
1000
0
Adults
sPCBs sCHLa sDDTs Dieldrin sHCH HCB sPBDEs sPCBs sCHLa sDDTs Dieldrin sHCH HCB sPBDEs
Contaminant group Contaminant group
Individuals showing periodontitis Individuals not showing periodontitis
Figure 4
Mean (SD) of various organohalogens (ng/g l.w.) in adipose tissue of subadult and adult polar bears sampled in East Greenland,
1999-2002 (n=79). Black bars indicate individuals showing periodontitis (4 subadults and 26 adults, respectively) and white bars
indicate bears not showing periodontitis (39 subadults and 10 adults, respectively).
Organohalogen concentrations
We investigated if there was a difference in the levels of organohalogens
between individual showing periodontitis and individuals not having periodontitis
within each group of age/sex group (subadults and adults respectively)
(Fig. 4). This data explorance showed that there was no statistical
significant difference in mean levels of organohalogen compounds in bears
with and bears without periodontitis for any of the contaminants analysed
(all: p>0.1) (Fig. 4).
Discussion
Wildlife and periodontitis
In the present study, there was no difference in the frequency of periodontitis
between the pollution period and the pre-pollution in any of the age
groups (Fig. 3), and the present results are therefore not in agreement with
reports of skull bone lesions in harbour seals (P. vitulina) and grey seals (H.
grypus) from Swedish and Danish waters. In these reports, lesions (periodontitis,
often with substantial loss of alveolar bone in mandible and maxilla,
and alveolar exostosis) were correlated to environmental pollutant levels
(Bergman et al. 1992, Mortensen et al. 1992). Schandorff (1997) also found
that for harbour seal (P. vitulina) a significant difference in the prevalence of
periodontitis between non-polluted and polluted decades. The adipose levels
of PCBs and DDTs found in these seal studies were significantly higher
than in the present polar bears, which may explain why we did not find a
contaminant-related time trend. The peridontitis complex also may not be a
sensible parameter for organohalogen exposure. In Table 1 the organohalogen
concentrations in seals from Danish and Baltic waters are compared to
the present East Greenland polar bears.
137