Organohalogen concentrations and a gross and histologic ...

More documents

Recommendations

Info

186 on the IgG levels (Bernhoft et al., 2000, Lie et al., 2004, Lie et al., submitted). Several studies have shown that OHCs such as PBDEs, PCBs, DDTs, 3- MeSO 2 -4,4’-DDE, MeSO 2 -PCBs, HO-PCBs and other halogenated phenolic compounds including HO-PBDEs and 4-HO-heptachlorostyrene, have the potential of functioning as endocrine disruptors (Hakk and Letcher 2003, Legler and Brouwer 2003, Letcher et al., 2000, 2002, Sandau et al., 2000). With the exception of HO-PBDEs, tissue residue concentrations of congeners from all classes of these OHCs have been determined in polar bears. These investigations support the hypothesis that OCs have the potential to affect the immune and hormonal system, and can consequently elicit lower immune response. Table 2 Basic statistics of the levels of contaminants in adipose tissue of the 23-year-old female polar bear with enlarged clitoris, with reference to 24 adult East Greenland female polar bears and one adult East Greenland male polar bear. PCBs, PBDEs, DDTs, HCHs and CHLs in ng/g l.w. Coplanare nPCBs, dioxins and furanes in liver: ng/kg (=pg/g) l.w. ”s”: sum; TEQ: Toxic Equivalents (pg/g l.w.).”.” indicates missing TEF-values or missing values due to detection limit. *: measure not included in the 95% confidence interval of the observations. Variable Female with enlarged clitoris Reference group Mean ± t0.95 * SD Min-max N Standard OCs: Level TEQ ΣPCBs 2707.7 . 6984.4±9521.5 887.2-20346.9 24 ΣPBDEs 32.87 . 60.9±68.7 57.9-16.8 24 ΣDDTs 374.2 . 361.4±553.4 73.5-1112.5 24 ΣHCHs 128.3 . 235.3±444.7 14-817.6 24 ΣCHLs 898.8 . 1895.1±3072.8 353.6-8132.1 24 Coplanar nPCBs: CB-37 1.76 . 3.6±9.1 0.58-7 4 CB-77 4.26 0.00426 11.2±18.7 3.9-16.3 4 CB-81 0.67 0.00067 4.1±16 0.62-11.48 4 CB-126 25.27 2.527 62±76.2 26.61-79.71 4 CB-169 73.31 0.07331 90.1±187.8 36.47-172.71 4 CB-189 19.82 0.01982 99.5±310.4 6.68-236.23 4 PCDDs: 1,2,3,7,8 PCDD 1.16 0.58 1.96±2.7 0.78-2.64 4 1,2,3,4,7,8 HxCDD 0.47 0.047 0.42±0.45 0.28-0.56 4 1,2,3,6,7,8 HxCDD 1.88 0.188 2.3±2.8 1.25-3.20 4 1,2,3,4,6,7,9 HpCDD 0.33 . . . 4 1,2,3,4,6,7,8 HpCDD 0.70 0.007 0.54±0.88 0.35-0.74 4 1,2,3,4,6,7,8,9 OCDD 4.14* 0.00414 0.92±1.88 0.32-4.14 4 PCDFs: 1,2,4,6,8 PCDF 0.05 . 0. 1±0.19 0.05-0.17 4 1,2,4,7,8 PCDF 0.33 . 0.32±0.67 0.14-0.61 4 2,3,4,7,8 PCDF 0.65 0.325 1.46±2.09 0.65-2.13 4 1,2,3,4,7,8,9 HpCDF 0.34 0.0034 0.38±0.68 0.23-0.53 4 1,2,3,4,6,7,8,9 OCDF 0.82 0.00082 0.79±1.4 0.33-1.39 4 Total TEQ 3.78
The relatively low levels of analysed OHCs in the old female polar bear with enlarged clitoris are probably a result of gestation and lactation as it is known that up to 70% of the total body burden are transferred transplacentally from mother to foetus (Bernhoft et al., 1997, Polischuk et al., 2002). The levels of ∑PCBs (ng/g) in the present female polar bear have been compared to levels of effects published in de March et al., (1998) and AMAP, (2004) (Table 3A). The level of ∑PCBs in the aberrant female polar bear was at sample time 2708 ng/g l.w. which is not in the range thought to negatively influence reproduction or elicit immunotoxicological effects. ∑PCBs (3033 ng/g w.w) were well below the concentrations (Table 3A) reported to cause reproductive or immunotoxicological effects in harbour seal (Phoca vitulina) (16500 ng/g l.w.), ringed seals (77000 ng/g l.w.), otters (Lutra lutra) (4000 ng/g l.w.), mink (Mustela vison) (40000 ng/g l.w.) and Rhesus monkeys (Macaca mulatta) (21000 ng/g l.w.) (de March et al., 1998, AMAP, 2004). Dioxins and dioxin-like compounds (TEQ values) The premise of the TEQ concept applied to non-ortho and mono-ortho chlorine-substituted PCBs is to equate the "dioxin-like" induction capacity via the aryl hydrocarbon receptor (AhR)-mediated mechanism using "mammalian" toxic equivalency factors (TEFs), and thus expressing the ∑coplanare PCBs concentrations after adjustment for the dioxin-like potency relative to 2,3,7,8-TCDD (van den Berg et al., 1998). AhR-mediated enzyme induction in mammals includes the CYP1A group (CYP1A1 and CYP1A2) and also recently identified CYP1B1 isozymes (Lin et al., 2003). Induced CYP1B1 and CYP1A1 enzymes can bioactivate exogenous compounds in the body (e.g. PCB congeners into HO-PCBs and other metabolites), and endogenous compounds in the body to toxic forms (e.g. CYP1B1-mediated metabolism of 17β-estradiol and estrone into carcinogenic 4-hydroxyestrogens), and/or can disrupt the homeostasis of estrogen hormones (van Duursen et al., 2003). nPCBs, dibenzofurans (PCDFs) and dibenzo-p-dioxins (PCDDs) in the present aberrant female polar bear were compared with three female polar bears (4-22 years) and one 6-year-old male polar bear from East Greenland (Table 2). One of the analysed PCDDs, 1,2,3,4,6,7,8,9 OCDD, in the aberrant bear differed from the values of 4 reference polar bears probably due to random biological variance (Table 2). The TEQ concentration comprised of nPCBs, PCDDs and PCDFs in the female polar bear with enlarged clitoris was 3.78 pg/g l.w. (Table 2) and is suspected to be lower than earlier in her life cycle (Bernhoft et al., 1997, Polischuk et al., 2002). In fact, based on time trends in the Arctic (e.g. AMAP, 2004, Dietz et al., 2004), the general OC exposure during her embryonic development was significant higher due to her heavily polluted mother, who is suspected to have carried organohalogen loads 2-3 timer higher (Ibid.). Compared to de March et al., (1998) and de AMAP, (2004) the total TEQ value (3.78 pg/g l.w.) for the present polar bears is 100-1000 times lower than thresholds known from seals and mink; and is generally comparable to terrestrial biota low on the food web (Table 3B). 187
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 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 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: SC II PC/LC Figure 2 The histology
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?