----- forwarded message -----
Date: Fri, 16 Jan 2004 06:22:47 -0700
From: Teresa Binstock <[EMAIL PROTECTED]>
Subject: Tiny particles 'threaten brain' - microscopic pollutants
Tiny particles 'threaten brain'
By Alex Kirby
BBC News Online environment correspondent
Published: 2004/01/08 16:05:26 GMT
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/3379759.stm
Microscopic pollutant particles given off by traffic and industry can enter the
bloodstream and the brain after being inhaled, scientists have found.
The particles are known to cause lung damage in susceptible patients, and are
implicated in cardiovascular disease.
Experiments on rats and humans have now discovered they can penetrate
further into the body, with unknown results.
UK scientists are calling for vigilance over the finding, and over the possible
effects of a new group of particles.
These objects are being created in the burgeoning field of nanotechnology, in
which atoms and molecules in materials are manipulated to exploit novel and
sometimes unusual properties.
Mindful of the potential health impact of such particles, the UK Government has
asked the Royal Society and the Royal Academy of Engineering to review the
current status of the science and assess if there is a need for new regulation.
Subtle infiltrators
Many of us are routinely exposed to particles from diesel vehicle fumes (these
are normally known as PM10, from their size), which penetrate buildings and
are ubiquitous in cities.
Some cooking stoves emit high levels of particles as well.
There is also occupational exposure for people making products like sunblock
cream, inks, photocopier toners, and working with welding equipment.
Ken Donaldson, Professor of Respiratory Medicine at the University of
Edinburgh, UK, said these sorts of particle were known to cause damage at the
point of entry to the human body.
What was new, he said, was the discovery by researchers in Europe and the
US that they "can get to areas that bigger particles cannot reach".
Patients who inhaled radioactive ultrafine carbon particles displayed traces of it
in their bloodstream not long afterwards.
Experimental rats which inhaled similar particles showed a marked decline in
particulate level in their lungs after six or seven days.
Unknown hazard
In the olfactory bulb and other parts of the brain, though, levels (although
lower than in the lungs) remained relatively stable over the same period.
These very small pieces of matter are called nanoparticles, defined as anything
smaller than 100 nanometres in size. A nanometre is one-billionth of a metre,
80,000 times smaller than a human hair.
Professor Donaldson said: "We are already exposed to nanoparticles of
different kinds. We already recognise that there is some ill-health associated
with these exposures.
"But they may also translocate away from their point of entry into the blood or
the brain. We are not sure what the consequences of this are yet.
"The nanotechnology revolution may design particles that are very different
chemically from the ones we are exposed to, and they might have very
different properties that made them more harmful. We should be vigilant."
He told BBC News Online: "I think there could be an increased future risk for all
of us, and also a higher risk for people exposed at present to nanoparticles at
work, though it's impossible to say how much bigger their risk is.
"These particles are not things you can trap with a filter. But they do disperse
rapidly, unlike asbestos."
Nanotechnology involves building working devices, systems and materials
molecule by molecule, and exploiting the unique and powerful electrical,
physical and chemical properties found at that scale.
It has developed from advances in microscopy, materials science,
molecular-level manipulation, and the relationship between classical and
quantum physics.
The UK's Royal Microcopical Society and the Institute of Physics are holding a
conference on the health implications of nanoparticles on 13 and 14 January at
the Daresbury Laboratories in northern England.
© BBC MMIV
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