快猫短视频

DUST clouds could come back to haunt the people who create them. In
California, where dust is a serious problem, researchers have developed a way of
tracing it back to its source using DNA fingerprinting.

Activities such as ploughing, harvesting and building work kick up enough
dust in California鈥檚 central valley to cause respiratory problems such as asthma
throughout the state. The smallest particles lodge deep in the lungs, causing
inflammation or infection. Until now it鈥檚 been difficult to work out where the
most obnoxious dust comes from.

But then researchers thought of trying DNA. 鈥淭here鈥檚 much more biological
information in 100 milligrams of dust than in its mineral content,鈥� says Kate
Scow, a soil ecologist at the University of California at Davis.

For seven years, Scow and her colleagues have collected the fingerprints of
soil from around California for ecological studies. They found that the
collection of bacteria and fungi in any one field produces a unique DNA profile,
and a unique mix of fatty acids which can be viewed by chromatography.

Scow and graduate student Mara Johnson then analysed the dust from some of
these soils and compared it with the soils themselves. It鈥檚 easy to tell where a
dust sample came by its DNA fingerprint, Johnson told the American Society for
Microbiology meeting in Los Angeles last week.

鈥淔inding ways to trace dust to its source allows you to deal with the worst
problems without spending millions,鈥� says Tony Van Curen, a pollution specialist
with the California Air Resources Board. 鈥淭his is one of the approaches we are
most excited about.鈥�