Health affects are associated with respirable
fiberous dust, i.e. unit density particles with a diameter less than
7 micrometers. Fibres and dust satisfying this criteria are capable
of reaching the nonciliated portion of the lungs where gas exchange
Asbestos fibres are 2000 times thinner
than human hair and are resistant to chemical decomposition and in particular
Asbestos fibre masses tend to break easily
into dust composed of tiny particles. Breathing in air containing asbestos
fibres may induce inflamation in the lungs that in turn generates oxidants
that can lead to asbestos related diseases (ARD's) mainly cancers of
the lung and the chest lining.
A Piece of Blue Asbestos
All types of asbestos are classed as
category 1 carcinogenic. Fibre length, biopersistance and inflamation
are the major determinants of fibre toxicity and carcinogenicity.
Asbestos is only
a risk to health if asbestos fibres are released into the air and breathed
Within industry a safe
maximum level of exposure has been agreed, however scientific evidence
on what precise level of exposure causes disease is unclear.
to asbestos currently kills 3500 - 5000 people a year in Great Britain.
This number is expected to continue to rise for the next 10 years.
There is no cure for
Asbestos related diseases. Only by minimising or preventing exposures
to asbestos fibres now, will asbestos related diseases (ARD's) be wiped