thanks to hairdresser Phillip McCrory from Alabama, usa, we now have a potential weapon against oil spills - those hair-raising environmental nightmares. Inspired by the media coverage of the 1989 Exxon Valdez oil spill, McCrory asked himself a very interesting question: if oil can coat animal fur readily, why not human hair? And that one query drove him to experiment with litres of motor oil and bundles of hair in his son's paddling pool. The results were satisfactory, and he took his idea to the us National Aeronautics and Space Administration's (nasa's) technology transfer experts at the nearby Marshall Space Flight Center in Huntsville.

Oil, as these experts discovered, does not soak into hair fibres, but it does stick to the scales on the surface. Human hair, however, works very well and is readily available.Further, since cleanliness of the hair is no problem at all, the nasa experts use hair straight from McCrory's shop. While oil sticks to the surface, water runs off the oily layer, leaving the oil behind (New Scientist, Vol 158, No 2134).

nasa experts tested their hair filter with a mix of three parts water to one of oil. After just a single pass through the filter, only 17 parts per million of oil remained. The filter is reusable, nasa has confirmed further. Cheap, the method costs around us $0.5, almost one-third of the conventional cleaning costs. Excited by the prospects, nasa is currently working on a practical design for hair-based oil filters.