Organohalogen concentrations and a gross and histologic ...

More documents

Recommendations

Info

10 not pseudohermaphroditism - probably caused by licking and biting (resembling acral lick dermatitis in the domestic dog). Except for the clitoral enlargement, all dimensions of the external and internal reproductive organs of this bear were similar to a reference group of 23 normal adult female polar bears from East Greenland collected in 1999-2002. Also, the female bear showed normal genotype, and macroscopic examination of her internal reproductive organs indicated that she was reproductively functional. Concentrations of organohalogens in subcutaneous adipose tissue showed that mean levels were up to 3 times lower than in the reference group animals, and lower than the threshold levels of known exposure to these compounds. But, the relatively low levels of analysed OHCs, in the old female polar bear with enlarged clitoris, were probably a result of gestation and lactation, as up to 70% of the total body burden is transferred transplacentally and via lactation from mother to foetus and cub. Therefore, these present levels cannot give any information about the old females' exposure prenatally (in utero) during her embryologically development, in which – if the diagnosis had been pseudohermaphroditism – these reproductive organ abnormalities would have been initiated. In conclusion, the histological examination showed that the enlargement was due to inflammation and not pseudohermaphroditism, why at least some of the previously reported pseudohermaphrodite adult female polar bears from Svalbard may in fact have been misdiagnosed. In conclusion, our results suggested a decrease in adipose tissue concentrations of organohalogens in East Greenland polar bears from 1990 to 1999- 2001. Two of the biological effect parameters (FA and enlarged clitoris) did not indicate a link to the relatively high levels of organohalogens. But, there were indications of strong relationships between various organohalogen compounds and skull mineral density indicating disruption of the bone mineral composition. The histopathological changes found in liver- and renal tissue were a result of ageing, infectious agents, season and meaby chronic exposure to organohalogens.
Resumé Betydelige mængder svært nedbrydelige organiske miljøgifte, som for eksempel PCBer og DDTer, er på grund af deres fedtopløselige egenskaber ophobet i arktiske havpattedyr – og i særdeleshed den østgrønlandske isbjørn (Ursus maritimus) – siden 1960erne. Mange af disse stoffer efterligner kroppens naturlige steroid- og peptidhormoner, hvorved de - gennem påvirkning af den normale fysiologiske homeostase - kan forstyrre hormonsystemer, forplantningsevne og immunologiske funktioner. Selvom disse biologiske effekter er blevet studeret i isbjørne på Svalbard de sidste 10 år, er der stadig mange uafklarede spørgsmål, og på det seneste er der fra norsk og canadisk side fokuseret på effekstudier af kønshormoner, cortisol, vitamin A og skjoldbruskkirtelhormon samt immunologiske, reproduktionsmæssige og overlevelsesrelaterede parametre. I forbindelse med disse undersøgelser er der meget som peger på, at specielt PCBer virker immunsuppremerende, udover at de også ændrer de normale hormonniveauer. Det er dog umuligt at afgøre, om disse resultater er et udtryk for virkelige årsagssammenhænge. Til at afklare dette, er kontrollerede studier af arktiske toppredatorer som f.eks. polarræv (Alopex lagopus) og slædehund (Canis familiaris) velegnede. Sådanne studier er sat i gang i Norge og på Grønland. For at afdække ikke tidligere undersøgte biologiske parametre i isbjørne i relation til organiske miljøgifte, startede vi en indsamling af prøver fra subkutant fedtvæv, indre organer og kranier fra mere end 100 østgrønlandske isbjørne (69˚00’N til 74˚00’N) via lokale fangere bosiddende i Scoresbysund i perioden 1999-2002. Nærværende afhandling afrapporterer de første resultater af studiet som søger at afdække, om de relativt høje niveauer af organohalogener opkoncentreret i fedtvævet har påvirket skeletsystemet (kranier) og indre organer. Det første manuskript behandler analyseresultaterne af organokloriner (PCB, DDT, chlordaner, dieldrin, HCH og HCB) i subkutant fedtvæv fra 92 individer indsamlet fra 1999 til 2001. Generelt udviste koncentrationerne kønsog aldersafhængighed, ligesom der var sæsonmæssige variationer for alle aldersgrupper. Disse nye prøver blev sammenlignet med tidligere analyser af bjørne indsamlet i 1990, hvilket viste et fald på mellem 20% og 70% afhængig af hvilken kontaminantgruppe man kigger på. Dog skal man passe på med endeligt at konkludere hvor stort faldet er, idet beregningerne kun bygger på to indsamlingsår (normalt kræver sådanne beregninger mindst 3 indsamlingsår over en 10-årig periode). Beregningerne viste desuden, at halveringstiderne for organokloriner i subkutant fedtvæv for Østgrønlandske isbjørne baseret på indsamlingerne i 1990 og 1999-2001 var fra 4 til 20 år, og dermed afspejler de svært biologisk nedbrydelige kontaminanter. Sammenlignet med tidligere studier af vilde pattedyr og fund i forbindelse med laboratorieforsøg, svarer niveauerne til, hvad man tidligere har benyttet som effektkoncentrationer for mange af de undersøgte parametre i nærværende afhandling. Det andet manuskript analyserer fluktuerende asymmetri (FA) i 283 isbjørnekranier indsamlet i perioden fra 1892 til 2002. FA udtrykker højrevenstresidig forskel for bilaterale mål, og denne forskel er positivt korreleret til, hvor stresset dyret er. Undersøgelsen koncentrerede sig omkring to formål, nemlig en tidstrend analyse og en analyse mellem FA og individuelle 11
Page 1 and 2: National Environmental Research Ins
Page 3 and 4: National Environmental Research Ins
Page 5 and 6: 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: elations between histological chang
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 and 58: of CYP-450 activity that impact cir
Page 59 and 60: Regarding renal tissue, we will try
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
Page 111 and 112:
Also Pertoldi et al. (1997) investi
Page 113 and 114:
study could not document a relation
Page 115 and 116:
Lie E, Bernhoft A, Riget FF, Beliko
Page 117 and 118:
function in harbour seals (Phoca vi
Page 119 and 120:
(p=0.94). Negative correlation betw
Page 121 and 122:
Osteodensitometry X-ray osteodensit
Page 123 and 124:
Figure 2 BMD (g cm 2 ) in skulls fr
Page 125 and 126:
Table 3 Significant results from th
Page 127 and 128:
2003) and plasma retinol and thyroi
Page 129 and 130:
Comiso JC. 2002. A rapidly declinin
Page 131 and 132:
Manalagas SC, Jilka RJ. 1995. Bone
Page 133 and 134:
Valentine DW, Soulé M. 1973. Effec
Page 135 and 136:
have the potential for adverse heal
Page 137 and 138:
Dioxin-like contaminants Extraction
Page 139 and 140:
Concentration 9000 8000 7000 6000 5
Page 141 and 142:
Acknowledgements Danish Cooperation
Page 143 and 144:
Polischuk, S. C., R. J. Letcher, R.
Page 145 and 146:
Paper IV Liver histology of free-ra
Page 147 and 148:
Histology All tissue samples were t
Page 149 and 150:
Figure 1 Hepatic lipid accumulation
Page 151 and 152:
Figure 2 Left: Portal mononuclear c
Page 153 and 154:
Relationship between histology and
Page 155 and 156:
kinson 1996). Due to these mechanis
Page 157 and 158:
sues. Arctic Monitoring and Assessm
Page 159 and 160:
van Duursen, M.B.M., Sanderson, J.
Page 161 and 162:
Introduction Polar bears (Ursus mar
Page 163 and 164:
Briefly, ∑PCBs is the sum (s) of
Page 165 and 166:
Figure 1 Bottom: example of glomeru
Page 167 and 168:
Figure 3 Tubular cell proliferation
Page 169 and 170:
Hyalin casts Hyalin casts were eval
Page 171 and 172:
Figure 6 Hyperemia (arrows) in the
Page 173 and 174:
al., 2003). We did not find such a
Page 175 and 176:
ANDERSEN, M., E. LIE, A. E. DEROCHE
Page 177 and 178:
LUROSS, J. M., M. ALAEE, D. B. SERG
Page 179 and 180:
organic mercury in liver and kidney
Page 181 and 182:
Introduction Polar bears (Ursus mar
Page 183 and 184:
Macroscopic examination of reproduc
Page 185 and 186:
Results and discussion The female p
Page 187 and 188:
SC II PC/LC Figure 2 The histology
Page 189 and 190:
The relatively low levels of analys
Page 191 and 192:
(Table 4), and we therefore conclud
Page 193 and 194:
Acknowledgements Danish Cooperation
Page 195 and 196:
Letcher RJ, Klasson-Wehler E, Bergm
Page 197 and 198:
Swart RL, Ross PS, Vedder LJ, Timme
Page 199 and 200:
10. Heier, A., C. Sonne, A. Gröne,
Page 201 and 202:
crine organs and skulls in the East
Page 203:
To investigate the relation between
show all

Organohalogen concentrations and a gross and histologic ...

Create successful ePaper yourself

Delete template?

Save as template?