Dandruff in the Atmosphere

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http://news.independent.co.uk/world/science_technology/story.jsp?

story=627927

 

Dandruff is as bad for the Earth as it is for your image

By Geoffrey Lean, Environment Editor

10 April 2005

 

 

Millions of tons of dandruff are circling the Earth, blocking out

sunlight, causing rain and spreading disease, startling new research

shows.

 

Flaky as it may seem, the research - partly funded by the German

government - may provide the solution to one of the world's most

enduring pollution mysteries: the origin of much of the vast clouds

of fine dust in the atmosphere. It suggests that more than half of

the dust is a rich soup of organic detritus, including particles of

decaying leaves, animal hair, dead skin and dandruff.

 

The research is published in the April issue of Science magazine by

Dr Ruprecht Jaenicke of Mainz University - who has been leading the

study for the past 15 years - and says " it has got to be taken very

seriously " .

 

The discovery has intrigued scientists, who have long known that

countless billions of tiny particles - some 8,000 times smaller than

the thickness of a human hair - are wafted around the globe,

affecting the climate and reducing the amount of sunlight reaching

the earth by one 10th, with incalculable consequences for agriculture.

 

It is known that about 60 per cent of them come from pollution, soot,

dust, ash, desert sand and sea salt, but the origin of the rest has

remained a mystery.

 

Now after taking air samples from the Amazon to Greenland, and

Germany to Russia's Lake Baikal, Dr Jaenicke calculates that there

are a billion tons of organic detritus in the atmosphere.

 

" Whenever you brush your hair or take off a sweater, you release a

cloud of biological dust, " he says. " When a bird flies through the

air it leaves behind particles from its feathers, and when the wind

blows through a tree it releases dust from the leaves. "

 

He has, however, not yet done the work to break down the constituents

of the dust clouds, so that he can tell precisely how much is

dandruff.

 

He says that the particles take up water in the atmosphere, and that

ice forms around them, increasing rainfall. But their effect on

global warming is unclear, as they would be involved in different

processes to increase or modify it.

 

Dr Gene Shinn of the US Geological Survey believes that the discovery

could help to explain the epidemic of asthma around the world. He

says that levels of the disease have soared in the Caribbean after

increases in dust borne across the Atlantic Ocean.