Breathe easy

日期:2017-06-06 03:28:06 作者:席嗖远 阅读:

By Andy Coghlan A NOVEL bedding material can starve tiny creatures that cause asthma to death. Developed by the British textile company Courtaulds, the new fabric contains substances that are harmless to humans but lethal to the house dust mite, Dermatophagoides pteronyssinus, which lives in bedding and whose faeces can trigger asthma. What makes the new material so unusual is that it attacks the fungi on which the mites depend, not the mites themselves. The usual way of controlling mites is to kill them with powerful pesticides or to seal mattresses in plastic covers. Now David Service and his colleagues at Courtaulds have discovered a new way to kill the mites, which they have developed in conjunction with John Maunder and David Thompson of the University of Cambridge and Trevor Cartlidge of Nottingham Trent University. In their experiments on a simulated bed, strewn with fragments of human skin and infested with the mites, the investigators discovered that the creatures cannot survive without the help of a fungus which they carry around on their bodies. The fungus, Aspergillus repens, pre-digests the flakes of human skin into a form which the mites can eat. Without this pre-treatment, the skin is indigestible to the mites, the Cambridge team discovered. “It’s like us trying to eat wood,” says Service, the head of the project and the research manager at Courtaulds. The researchers reasoned that the mites would die out if the fungus could be destroyed. So they spiked cotton and other bedding fabrics with a fungicide lethal to A. repens. “It’s similar to the one used in athlete’s foot treatments,” says Service. The fungicide is incorporated into the cores of bedding fibres as they are spun, from where it migrates slowly to the fibre surface. “It’s a slow-release mechanism, and can’t be washed out,” says Service. The bedding materials, which include sheets, duvets, pillows, mattresses and covers, are also impregnated with triclosan, a compound that kills the bacteria which make underclothes and socks smell. Courtaulds last year launched sports socks and underwear incorporating the same antibacterial substance. Marketed by the sportswear firms Reebok and Berghaus, the items are said to have sold well (This Week, 1 March 1997, p 21). Courtaulds has already launched the bedding materials to combat dust mites. It is selling them in Britain through the Textile World chain and hopes to sign up other major retailers. The company is keeping the identity of the fungicide a secret, and has waited for patent applications to be granted before disclosing this new approach. Service says that the substances added to the sheets are unlikely to trigger allergies. “You can eat them,” he says. “You’re more likely to develop an allergy to cotton.” Britain’s National Asthma Campaign, which estimates that 3.4 million Britons suffer from the disease, said it looked forward to evaluating the new findings, but warned against overoptimism. “It’s good news if it works,” says a spokeswoman, though she warns that for maximum effect, curtains,