Updates; July 2008; Scientific American Magazine; by Philip Yam; 1 Page(s)

The Antarctic ozone hole that forms every spring has kept that continent¿s interior cold even as the rest of the world has warmed over the past few decades [see ¿A Push from Above¿; SciAm, August 2002]. Thanks to the global ban on chlorofluorocarbons, stratospheric ozone levels there are slowly recovering. A repaired hole, however, could speed Antarctic ice melting and change weather patterns, according to a computer model by Judith Perlwitz of the University of Colorado at Boulder and her colleagues. With more ozone, the lower stratosphere would absorb more ultraviolet light and warm up by as much as nine degrees Celsius. That in turn would break down circulation patterns that trap cold air over Antarctica¿s interior, making the continent heat up. The changed patterns would also make Australia warmer and drier, and South America could get wetter. Such ozone details may need to be worked into global climate models, most of which have neither incorporated such effects nor included enough of the stratosphere. The journal Geophysical Research Letters published the study on April 26.

"Scientists remain on the lookout for novel drugs that combat radiation damage. One of the most promising is CBLB502, made by Cleveland Biolabs in Buffalo, N.Y. [see ¿Surviving Side Effects¿; SciAm, October 2007]. In the April 11 Science, researchers report that the drug, also called Protectan, enabled 87 percent of mice to survive lethal doses of radiation, although it worked only if injected within an hour before exposure. (It showed some protective effects if injected after exposure to lower levels of radiation.) The compound, which could be given in the event of a nuclear explosion or meltdown, did not shield malignant cells, so it could protect healthy cells of cancer patients undergoing radiation treatment. The company now needs to test the agent in large numbers of people."