News Scan Briefs; June 2008; Scientific American Magazine; by Keren Schultz, Charles Q. Choi, David Biello, Nikhil Swaminathan; 2 Page(s)

Breathing in asbestos and silica has long been known to cause lung damage, but how the damage occurs has been a mystery. Using mice, scientists have now zeroed in on a key player known as the Nalp3 inflammasome, a complex of proteins that serves as a potent alarm system in our bodies. Evidently, when the body breaks down inhaled asbestos fibers, it ultimately produces reactive oxygen that triggers the inflammasome, which in turn causes lung inflammation. Mice that lack the Nalp3 inflammasome have a reduced reaction to asbestos. According to study co-author Jürg Tschopp of the University of Lausanne in Switzerland, the finding suggests that people exposed to asbestos should be checked for inflammation of the lung, which may be apparent 10 years after exposure. Also, because Nalp3 lies behind other immune reaction conditions, such as gout, the team speculates that gout medicine might slow the progression of inflammatory lung disease. Science published the results online April 10.

A nuclear exchange between India and Pakistan could globally harm the ozone layer, according to computer simulations. If those nations each launched 50 Hiroshima-level nuclear weapons¿a total of 1.5 megatons, or just 0.03 percent of the total explosive power of the world¿s nuclear arsenal¿smoke from burning cities would loft up as much as five million metric tons of soot. This ash would eventually rise to stratospheric heights of up to 80 kilometers, where it would trigger ozone-destroying reactions. As much as 70 percent of the ozone above the high northern latitudes would get lost, a depletion comparable to the Antarctic ozone hole. Up to 45 percent of the ozone above the earth¿s midlatitudes, where most of the world¿s population lives, would also vanish. As stratospheric ozone diminished, ultraviolet light¿triggered cancer and other forms of serious damage would rise sharply. The analysis, which appeared online April 7 in the Proceedings of the National Academy of Sciences USA, suggests that the ozone would begin to recover only after five to eight years.