Bili Buzz - Popular Science, Nature, Medicine, Archeology, Future & Myths

One step forward, one step back.

The good news is that the ozone hole over Antarctica is slowly healing, thanks to controls on ozone-depleting substances that were once widely used in products such as refrigerators and aerosol cans. Stratospheric ozone protects us from harmful ultraviolet radiation that can cause problems such as skin cancer and crop damage.

Unfortunately, the recovery of the ozone hole has a dark side: The return of a thin, suspended blanket of stratospheric ozone will raise temperatures over the southern polar region, according to a new study by scientists at the University of Colorado at Boulder, the National Oceanic and Atmospheric Administration, and NASA Goddard Space Flight Center. The scientists, who relied on a NASA computer model for their predictions, also report that the healing of the hole will weaken winds that currently shield the Antarctic interior from warmer air masses to the north.

Antarctica may not be the only continent affected: The researchers also found that the changes in air circulation caused by ozone recovery could mean wetter conditions during late spring and early summer in southern South America, and warmer and drier weather in Australia—which is already suffering from a long drought.

While average temperatures in most places on the globe have been increasing, the interior of Antarctica has experienced cooler summers and autumns. “We may finally see the interior of Antarctica begin to warm with the rest of the world,” says Judith Perlwitz, the lead author of the study, which will be published in the journal Geophysical Research Letters on April 26.

For all the problems greasy hair might bring, there’s at least once upside: lessened exposure to ozone. In a decidedly odd, though fruitful study, University of Missouri researchers Glenn Morrison and Lakshmi Pandrangi measured the ozone levels surrounding samples of washed and unwashed hair over the course of a day. Dirty hair absorbed seven times the amount of ozone. The grungy-haired, in other words, inhale one-seventh of the occasionally fatal respiratory irritant as their squeaky clean counterparts.

So, live dirty and prosper? Alas, it’s not quite that simple. Ozone levels are lowered by the interaction with hair funk, but only because of the chemical reactions that take place. A good chunk of human skin oils, 10-15 percent, are composed of (the terrifically named) squalene. The organic compound is replete with double bonds—something that ozone molecules react with “like crazy,” according to Morrison. Ozone levels might be lowered, but secondary reactions between the reactive molecule and squalene ensure there’s still some pretty bad stuff hanging around your head. The major lousy byproduct the researchers found was 4-oxopentanal—a different respiratory irritant.

Morrison is loath to draw any conclusions: “maybe there’s a net benefit, but we really couldn’t assume that.” But he notes the study underscores just how little we know about ozone. “Clearly our exposure is lower than we think, but our understanding of how it reacts with our body chemistry is pretty limited.” A policy of avoiding ozone—especially indoors—is still a prudent course of action. And until scientists figure out all possible secondary reactions, you may want to chuck that ionic filter.