Subscribe free to our newsletters via your
. Earth Science News .

Subscribe free to our newsletters via your

Contaminants May Cause Renal Lesions In Polar Bears

File photo: A Polar Bear.
by Staff Writers
Washington DC (SPX) May 16, 2006
Polar bears from East Greenland contain the highest recorded concentrations of organohalogen contaminants (OHCs)--more than any mammalian species in the world. Researchers in a new study suggest that these air- and seaborne chemicals could be part of the reason why this subpopulation has developed renal lesions. The study is published in the Environmental Toxicology and Chemistry.

The significance of the renal lesions is not well understood. This study provides the first evidence of adverse effects to polar bears from long-term exposure to OHCs, which include DDT, polychlorinated biphenyls (PCBs), and polybrominated diphenylethers (PBDEs).

PCBs and PBDEs are known for their ability to act as flame retardants. These compounds have hundreds of uses in such products as electronic circuit boards and cases, furniture, building materials, pesticides and lubricants.

Among the 75 polar bears examined in the study, seven different types of renal lesions were found. Six of the seven types were related to age.

However, because the lesions were similar to those of OHC-contaminated Baltic seals and other exposed laboratory animals, the authors decided that OHCs were a cofactor in the development of the renal lesions. Metals and recurrent infections were not ruled out as other possible factors.

In polar bears, OHCs are transferred from mother to fetus and to offspring by lactation. The study forms the basis for research on other OHC-contaminated wildlife and raises the possibility of OHC transfer to human populations who rely on what may be contaminated food sources in the Arctic.

Related Links
Society of Environmental Toxicology and Chemistry

Non-Coding RNAs Help Silence The Mammalian Transcription
Cold Spring Harbor NY (SPX) May 15, 2006
Dr. Shirley Tilghman and colleagues (Princeton University) lend new insight into the mechanism of genomic imprinting, demonstrating a necessary role for a non-coding RNA transcript in the silencing of an imprinted gene cluster in mice.

  • Dutch Soldiers Move Into Afghanistan Under Apache Protection
  • MSV Supports New Laws Boosting Satellite Communications Provisions For Emergencies
  • Indians At Risk In Afghanistan
  • Pacific Tsunami Alert System Tests To Start Mid-May

  • Clinton Says Climate Change Greatest Threat
  • Redirecting Mississippi River Proposed As Way To Save Louisiana Coast
  • Environmental Groups Urge Canada To Withdraw As Chair Of Bonn Talks
  • Climate change risks killing millions in Africa: charity

  • Tibet Provides Passage For Chemicals To Reach The Stratosphere
  • Raytheon Tests Advanced Space-Based Weather Sensor
  • African Wetland Managers Armed With New Technology
  • ESA To Host Atmospheric Science Conference

  • Scientists Create the First Synthetic Nanoscale Fractal Molecule
  • Greenpeace Urges ADB To Stop Funding Fossil Fuel Projects
  • Alternate Fuel-Powered B-52 To Fly In September
  • EADS And ASB To Create Of US Thermal Battery Company For The Military

  • NAU Receives Patent For Technique That Could Stop TB
  • Indian Government Intervenes In Stone Age Tribe Health scare
  • US Bird Flu Toll Could Be As High As 2 Million
  • H5N1 Adapts To Summer, Water, Heat

  • Dragonfly Migration Resembles That Of Birds
  • Contaminants May Cause Renal Lesions In Polar Bears
  • Larval-Stage Organisms Effect Measurements Of Marine Biodiversity
  • Non-Coding RNAs Help Silence The Mammalian Transcription

  • New "Toxic" Ship Bound For India
  • China Says River Clean After Thaw
  • China's "Cancer Villages" Pay Heavy Price For Economic Progress
  • Russian Ecologists Despair Over Lack Of Govt Vision

  • Guard Likely To Support Border Patrol Says National Security Adviser
  • Humanity May Have Caused Pre-Historic Extinctions
  • Evolutionary Forces Explain Why Women Live Longer than Men
  • Rwandan Pygmies Fight For Survival In Eco-Sensitive Times

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement