Tiny particles 'threaten brain'

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http://news.bbc.co.uk/2/hi/science/nature/3379759.stm

 

Tiny particles 'threaten brain'

 

 

By Alex Kirby

BBC News Online environment correspondent

 

 

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.

 

 

 

 

 

 

 

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