Environmentalists say it takes the fur of three to five Tibetan antelope, or chiru, to make one shahtoosh shawl. At that rate, there's little hope for the endangered species, whose population--somewhere between 75,000 and 100,000--is dwindling by the thousands each year. Found on the remote Qinghai-Tibetan plateau, the creatures are shot and skinned by poachers, who then smuggle the hair into India where it is woven into shawls.The chiru's hair is so fine that dealers pass a shawl through a ring to check authenticity. Even conservationists concede its superiority. It is indeed the king of wools, says Judy Mills, director of TRAFFIC East Asia, referring to the meaning of shahtoosh. It's fabulous. So fabulous, in fact, that in recent years, the fashion world has fueled demand to dangerous levels. From Hong Kong to the U.S., a single shawl made from the world's most expensive wool can fetch as much as $5,000.In Jammu and Kashmir, India's northernmost state and the only place a worldwide ban on trade in Tibetan antelope doesn't apply, workers in the industry deny the creatures are killed at all. Asks Hashmatullah Khan of the Kashmir Handicraft Traders Welfare Association: Who would kill the goose that lays the golden egg? Khan insists that weavers use only hair the animals leave behind after brushing against bushes and shrubs. Conservationists say that's a myth perpetuated by a misinformed retail industry. Urging an end to the shahtoosh trade, they point out that there aren't any bushes and shrubs on the plateau to brush up against.By YUSUF JAMEEL and WENDY KANHow can trash in the ocean possibly be useful? Ask oceanographer Curtis Ebbesmeyer, who specializes in tracking debris across the oceans and has a worldwide network of beachcombers to assist him (). His objective: to learn how tides and currents affect floating junk and gunk. His latest project: tracking 100,000 toy cars and 1 million party balloons that fell from a cargo ship near Japan in January. Seattle-based Ebbesmeyer says this flotsam will help him and fellow oceanographer W. James Ingraham Jr. find out how oil and toxic chemicals are dispersed in the ocean. With so many pieces afloat, Ebbesmeyer expects a better reading of how trash travels than expensive satellite equipment could provide. He says North Americans can expect the toy cars and balloons to wash up on their shores eventually--just not any time soon. Says Ebbesmeyer: Debris can take decades to cross the ocean.PERSONAL SMOG GAUGE: In most big cities, pollution alerts are as much a part of TV newscasts as the weather report. But that doesn't help you know how bad the air is right outside your door. Now a French firm, Pollucorp, has produced Pollumetre Air, a pager-size pollution reader. On sale in Hong Kong and Europe for $90, the device aims to help pregnant women, children, patients with respiratory ills and other especially vulnerable people by detecting too-high levels of carbon monoxide. Of course, there's a cheaper way to protect yourself: avoid places jammed with cars and motorbikes.SEEKING SENIORS: Environmental educators most often aim messages at kids. They're more receptive than their elders, and when it comes to saving the planet, it's their future at stake. But now conservationists are going after a new audience: senior citizens. They may have fewer years left on this earth, but what about their grandchildren? And retirees may have the time and money to plant trees or lobby legislators. Tips for interested old folks--or kids who want to get grandpa involved--can be had from the Environmental Alliance for Senior Involvement ().