Exposure to organochlorine chemicals is linked to reduced bone mineral density among polar bears from East Greenland, according to a study published today in the December issue of the peer-reviewed journal Environmental Health Perspectives (EHP). In the study of 139 polar bear skulls, researchers compared 41 samples collected between 1892 and 1932 with 98 samples collected between 1961 and 2002. Bone mineral density in the skulls collected before 1932—considered “pre-pollution” by the researchers—was significantly higher than that in skulls sampled in the “post-pollution” period after 1961, when scientists first began seeing organochlorines and other persistent organic pollutants (POPs) in the fat of polar bears.
The researchers also analyzed a subset of 58 skulls collected between 1999 and 2002 to examine the organochlorine body burden in relation to bone mineral density. In this group, exposure to PCB compounds and to chlordane (a now-banned insecticide) both correlated with low bone mineral density among younger bears. In adult males, concentrations of dieldrin (another banned insecticide) and total DDT residues also correlated with low density.
POPs resist breakdown, store easily in fat, and bioaccumulate through the food chain. Once widely used in agriculture and industry, several types have been classified as probably or possibly carcinogenic to humans, and there are now restrictions or bans related to their application. However, these highly toxic chemicals are very stable over time, and they remain widely present in the environment, where they still pose a serious health threat.
Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
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09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine