Organohalogen concentrations and a gross and histologic ...

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56 Perspectives and recommendations The present thesis contributes significantly to the understanding of the potential toxicity from organohalogen compunds in Arctic marine mammals. It fills out knowledge gaps of effects on bone and tissues necessary for the maintainance of endogeneous homeostasis. It clearly shows that more research in this field is needed to understand the potential effect on a population level for top predators – as the polar bear, Arctic fox and killer whale – in the Arctic. Contaminants Although we have showed that there may be a decrease of contaminants in the East Greenland polar bear from 1990 to 1999/2001, new contaminants are accumulated in the East Greenland marine food webs. New studies on brominated flame retardants (PBDEs) (Muir et al. In prep.) and PFOS (Smithwick et al. In prep., Bossi et al. Submitted) have shown that these may reach levels of concern for the health and reproductive status of the polar bears. Future investigations will monitor and assess these new problems. In addition cadmium and mercury concentrations will be considered as aetiological factors in the pathogenesis of the variable relations and lesions observed. In collaboration with canadian research groups we are in progress of investigating the relationship between concentrations of organohalogens in different compartments and tissues (liver, brain, kidney, subcutaneous adipose tissue and blood) in the East Greenland polar bear. Skulls No relation between periods of organohalogen pollution and FA in skulls was found. Neither did we find a relation between individual levels of organohalogens and skull FA. On the other hand we found strong indications of period differences in bone mineral density (proposed non-polluted period higher compared to proposed polluted period) and strong negative associations between bone mineral density and various organochlorines (PCBs, DDTs, chlordanes and dieldrin). It cannot be concluded if these are true cause-effect findings but this will hopefully be taken care of in our future investigations of organohalogen toxicity in West Greenland sledge dogs (see next Sections). Liver and kidney In the present study we found signs of chronic inflammation that probably is a result of age, infectious agents and food (lipids) but long-term exposure to anthropogenic toxic substances, such as organohalogens and heavy metals, cannot be ruled out. As we have an ongoing sampling programme in East Greenland we have the possibility of obtaining samples for cytokine investigations and electron microscopy (ultrastructural changes) which is included in the sampling period 2003-2006. In addition, levels of organohalogens will be analysed and compared to liver levels of retinol (vitamin A) as we will continue the investigation of retinol binding protein (RBP) (Heier et al. Submitted) in relation to organohalogens and levels of liver vitamin A.
Regarding renal tissue, we will try to dertermine the tubular pigments and see if these have a relation to mercurry accumulation (autometallography) (Woshner et al. 2002). Reproductive organs The morphology of both male (testicles) and female (uterus, oviducts and ovaries) reproductive organs will be investigated in relation to reproductive cycles and organohalogen levels. If possible, receptor diagnostics in relation to age, season and pollutants will be conducted. Comparative studies of domestic dog (Canis familiaris) and Arctic fox (Alopex lagopus) We are conducting a dose-response, case-control study on the Greenland sledge dog. The purpose of the study is to investigate whether the signs of osteopenia in relation to organohalogen body burdens, are true cause-effect interactions. The other main purpose is to find out whether the signs of chronic inflammation in kidney and liver could be due to the organohalogen exposure. Without going into details in the experiment setup, several other biological parameters will be analysed (vaccination response, CYP-isozymes, retinol levels, thyroid homones, sex steroids, cytokines a.o.). In addition we have a cooperation with Norwegian researchers who investigate the seasonal fasting of the Svalbard Arctic fox. They have an on-going controlled experiment from which we will get samples for analysis and vice versa. 57
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National Environmental Research Ins
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National Environmental Research Ins
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Contents Summary 7 Resumé 11 Prefa
Page 7 and 8: Paper III-b Periodontitis and tooth
Page 9 and 10: Summary Marine mammals in the Arcti
Page 11 and 12: elations between histological chang
Page 13 and 14: Resumé Betydelige mængder svært
Page 15 and 16: signifikante relationer blev fundet
Page 17 and 18: Preface Since ca. 1960 signficant a
Page 19 and 20: Acquarone, Poul Johansen and Inge B
Page 21 and 22: Abbreviations ∑ Sum of congeners
Page 23 and 24: Introduction Study area and samplin
Page 25 and 26: content and composition) varying wi
Page 27 and 28: Of the PCBs found in the East Green
Page 29 and 30: son Bay bears while the difference
Page 31 and 32: Individual levels and biological ef
Page 33 and 34: No. skulls collected 50 45 40 35 30
Page 35 and 36: temperature extremes and/or food av
Page 37 and 38: Chapter 3 Bone mineral density and
Page 39 and 40: BMD analysed by DXA reflects the ar
Page 41 and 42: Table 4 Range in the levels (ng/g l
Page 43 and 44: Chapter 4 Liver histology of East G
Page 45 and 46: Table 7 Levels of ∑-PCBs, ∑-DDT
Page 47 and 48: Frequency (%) 100 80 60 40 20 Sever
Page 49 and 50: Effects of PBBs (PolyBrominated Bip
Page 51 and 52: Etiology and pathogenesis E Figure
Page 53 and 54: common sign (Acland 1995, Feldman 1
Page 55 and 56: Conclusions and final assessments O
Page 57: of CYP-450 activity that impact cir
Page 61 and 62: Bernhoft, A., Ø. Wiig and J. U. Sk
Page 63 and 64: Feldman, E. C. (1995): Hyperadrenoc
Page 65 and 66: (eds.): Ringed seals in the North A
Page 67 and 68: McCormack, K. M., W. M. Kluwe, V. L
Page 69 and 70: Rosing-Asvid, A., E. W. Born and M.
Page 71 and 72: Valentino, R., S. Savastano, A. P.
Page 73 and 74: Paper I Seasonal and temporal trend
Page 75 and 76: eproductive rates of seals in the B
Page 77 and 78: concentrations of the 41 individual
Page 79 and 80: Figure 1 Capture locations of the p
Page 81 and 82: Table 4 Results of ANOVAs (F-value
Page 83 and 84: Long-Term Temporal Changes in OC Co
Page 85 and 86: Discussion Geographical Variation i
Page 87 and 88: sen et al. (2001) studied the trend
Page 89 and 90: higher than reported in other studi
Page 91 and 92: Bergman A, Olsson M. Pathology of b
Page 93 and 94: Muir D, Norstrom RJ. Geographical d
Page 95 and 96: Wiig Ø, Gjertz I, Hansson R, Thoma
Page 97 and 98: Key words: polar bear, Ursus mariti
Page 99 and 100: 2. Materials and methods 2.1 Sampli
Page 101 and 102: 2.3 Age Determination The age deter
Page 103 and 104: No. skulls collected 50 45 40 35 30
Page 105 and 106: Table 4 Results (test and p-values)
Page 107 and 108: Table 6 Results from F-tests (p-val
Page 109 and 110:
(oxy-chlordane, trans-chlordane, ci
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Also Pertoldi et al. (1997) investi
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study could not document a relation
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Lie E, Bernhoft A, Riget FF, Beliko
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function in harbour seals (Phoca vi
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(p=0.94). Negative correlation betw
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Osteodensitometry X-ray osteodensit
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Figure 2 BMD (g cm 2 ) in skulls fr
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Table 3 Significant results from th
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2003) and plasma retinol and thyroi
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Comiso JC. 2002. A rapidly declinin
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Manalagas SC, Jilka RJ. 1995. Bone
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Valentine DW, Soulé M. 1973. Effec
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have the potential for adverse heal
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Dioxin-like contaminants Extraction
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Concentration 9000 8000 7000 6000 5
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Acknowledgements Danish Cooperation
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Polischuk, S. C., R. J. Letcher, R.
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Paper IV Liver histology of free-ra
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Histology All tissue samples were t
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Figure 1 Hepatic lipid accumulation
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Figure 2 Left: Portal mononuclear c
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Relationship between histology and
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kinson 1996). Due to these mechanis
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sues. Arctic Monitoring and Assessm
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van Duursen, M.B.M., Sanderson, J.
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Introduction Polar bears (Ursus mar
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Briefly, ∑PCBs is the sum (s) of
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Figure 1 Bottom: example of glomeru
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Figure 3 Tubular cell proliferation
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Hyalin casts Hyalin casts were eval
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Figure 6 Hyperemia (arrows) in the
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al., 2003). We did not find such a
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ANDERSEN, M., E. LIE, A. E. DEROCHE
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LUROSS, J. M., M. ALAEE, D. B. SERG
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organic mercury in liver and kidney
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Introduction Polar bears (Ursus mar
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Macroscopic examination of reproduc
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Results and discussion The female p
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SC II PC/LC Figure 2 The histology
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The relatively low levels of analys
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(Table 4), and we therefore conclud
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Acknowledgements Danish Cooperation
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Letcher RJ, Klasson-Wehler E, Bergm
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Swart RL, Ross PS, Vedder LJ, Timme
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10. Heier, A., C. Sonne, A. Gröne,
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crine organs and skulls in the East
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To investigate the relation between
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