Reproductive performance in East Greenland polar bears (Ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (PBPK) modelling |
| |
| Institution: | 1. Sydney School of Veterinary Science, The University of Sydney, Camperdown, NSW 2006, Australia;2. Melbourne Zoo, Parkville, Victoria 3052, Australia;3. Sydney, NSW 2006, Australia;4. Australian Ultra Trace Laboratory, National Measurement Institute, North Ryde, NSW 2113, Australia;1. Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada;2. Department of Chemistry, Carleton University, Ottawa, ON, Canada;3. Government of Nunavut, Igoolik, NU, Canada;4. Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China;5. Ontario Ministry of the Environment and Climate Change, 125 Resources Rd, Toronto, ON, Canada;1. Norwegian Polar Institute, Fram Centre, Tromsø, Norway;2. Norwegian University of Science and Technology, Trondheim, Norway;3. The University Centre in Svalbard, Longyearbyen, Norway |
| |
| Abstract: | Polar bears (Ursus maritimus) feed mainly on ringed seal (Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health effects, including reproductive, were conducted during 1990–2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk quotient (RQ) evaluation to more quantitatively evaluate the effect risk on reproduction (embryotoxicity and teratogenicity) based on the critical body residue (CBR) concept and using a physiologically-based pharmacokinetic (PBPK) model. We applied modelling approaches to PCBs, p,p′-DDE, dieldrin, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats (Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79–1271 ng g?1 lw) and PCBs (range: 4128–53 923 ng g?1 lw) reported in bears in the year 1990 were in the range to elicit possible adverse health effects on reproduction in polar bears in East Greenland (all RQs ? 1). Similar results were found for PCBs (range: 1928–17 376 ng g?1 lw) and PFOS (range: 104–2840 ng g?1 ww) in the year 2000 and for dieldrin (range: 43–640 ng g?1 lw), PCBs (range: 3491–13 243 ng g?1 lw) and PFOS (range: 1332–6160 ng g?1 ww) in the year 2006. The concentrations of oxychlordane, DDTs, HCB and HCHs in polar bears resulted in RQs < 1 and thus appear less likely to be linked to reproductive effects. Furthermore, sumRQs above 1 suggested risk for OHC additive effects. Thus, previous suggestions of possible adverse health effects in polar bears correlated to OHC exposure are supported by the present study. This study also indicates that PBPK models may be a supportive tool in the evaluation of possible OHC-mediated health effects for Arctic wildlife. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
