response to the [myelin protein] pep tide, there are other myelin compo nents that elicit an immune response/7 But, he explains, in shutting off the im mune response to the protein peptide, the analog also prevented the immune system from responding to other pep tides in the myelin sheath. Probing this phenomenon further, the researchers discovered that the an alog binds Τ cells only weakly. They found it works by stimulating the im mune system to produce interleukin-4, the hormonelike compound that acti vates the immune system cells that nat urally fight inflammation. "It's unclear how the body turns off normal inflammatory reactions, such as the redness that occurs in a sore throat," Steinman notes. "We have found what may be one of the body's signals for stopping inflammation, and we hope to use it to treat disease." He points out that until now scientists have believed the only way to treat an autoimmune disease effectively is to suppress the entire immune system. His group's work shows it may be enough to block the initial mechanism that trig gers an autoimmune response—which could be significant in designing drugs for autoimmune diseases. Mairin Brennan
U.S. reveals size of chemical arms arsenal The Pentagon has officially disclosed what has long been suspected and widely whispered: The U.S. has more than 30,000 tons of nerve gas, blister, and choking agents stored at eight sites scattered across the U.S. and at one site on Johnston Atoll southwest of Hawaii in the central Pacific Ocean. This deadly arsenal is slated for dis posal by 2004 at an estimated cost of more than $12 billion. In 1986, when Congress mandated the destruction of these weapons, the estimated cost of disposal was about $1.6 billion. The Army, with lead responsibility for chemical arms, is planning to build an incinerator complex—called base line—at each storage site to destroy these stocks. But baseline has been plagued by technical glitches and con troversy. To date, the Army has built two incinerators: One, on Johnston Atoll, has destroyed less than 900 agent
U.S. stores more than 30,000 tons of chemical arms agents
tons in a decade; the other, at Tooele, Utah, is still undergoing testing. What is new in the Pentagon's effort at post-Cold War openness is the detail of disclosure, revealing the type and number of so-called unitary weapons— shells, rockets, and bombs—and the amount of cheinical agent stored at each site. The information is being released because these weapons and agents are "no longer considered part of the nation al stockpile that would be used for war,,r says George Friel, commanding general of the Army Cheinical & Biological De fense Command at Aberdeen Proving Ground, Md. "Therefore, it's no longer a national security interest and doesn't re quire ... classification," he adds. Presi dent Clinton renomiced use of cheinical weapons in 1993. Matthew S. Meselson, chemical war fare expert and Harvard University biochemistry professor, says it also "shows the determination of the Army to proceed with chemical demilitariza tion [destruction] as Congress has en acted and as the Chemical Weapons Convention will require." Robert Orton, who manages the Ar my's destruction program, offers practi cal and political reasons for the disclo sure. The Army is meeting stiff commu nity resistance to building incinerators. "This will help minimize misunder standings, expedite environmental per mitting processes, and save money. It also may enhance our credibility by con firming that we're not holding back from regulators and the public informa tion they need to operate."
But the Army won't easily overcome the resistance, says Craig Williams, spokesman for the Chemical Working Group, based in Berea, Ky., which op poses incineration. "The incineration program is unsafe and has failed." The Pentagon has also revealed for the first time the size of its binary chemical weapons stockpile (680 component tons) and an inventory of its so-called nonstockpile chemical materials. These are also slated for destruction, but not by 2004. Bi naries consist of two parts that are mated just before firing a shell. Firing causes chemicals to mix to fonn nerve gases. Binaries and the nonstockpile chemi cal materials are to be destroyed under the 10-year timetable set up by the Chemical Weapons Convention, which the U.S. has not yet ratified (see page 19). Wayne Jennings, deputy program man ager for the Army's nonstockpile chem ical materiel program, says binaries likely will be destroyed around 2005, while the other chemical materials will be destroyed throughout the 10 years. All the precursor chemicals needed to form a nerve gas in a binary weapon can be incinerated. And the Anny plans to seek commercial firms that handle haz ardous wastes to dispose of these chem icals. The Army will try to sell one pre cursor, isopropyl alcohol, if the chemical weapons treaty will allow this. In 1993, the estimated cost of disposal was about $190 million. The other nonstockpile chemicals are to be neutralized and dis posed of by commercial firms, Jennings explains. Lois Ember JANUARY 29, 1996 C&EN
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