Speaker
Dr
Anne Thoustrup Saber
(National Research Centre for the Working Environment, Copenhagen, Denmark)
Description
Different kinds of particles have been shown to induce
genotoxic damage after deposition in the lung. This may
result in cancer if the DNA damage is not repaired or if
selective apoptosis of the damaged cells fails. A primary
mechanism of particle-induced genotoxicity has been
attributed to the surface characteristics. A decade ago a
secondary pathway for genotoxicity was proposed on the basis
of the finding that carbon black exposed rats developed
tumours similar to DEP exposed rats, despite the fact that
carbon black is almost devoid of PAH´s on the surface. The
fact that tumour formation in rats has been found to be
paralleled by the degree of chronic neutrophilic
inflammation led to the idea about a relationship between
particle-induced inflammation and genotoxicity. Likewise,
most human cancers are accompanied by the infiltration of
inflammatory cells and a wide range of chronic inflammatory
diseases predispose to cancer in the affected organ. The
genotoxic effect of particle-induced inflammation is related
to the release of reactive oxygen species by the
inflammatory process. It has been demonstrated that the
inflammatory response depends on the particle size. Exposure
studies have shown that ultrafine particles cause more
inflammation in the lungs of rodents than exposure to the
same mass concentration of fine particles. The greater
surface area has been suggested to be responsible for the
greater inflammatory response of the ultrafine particles.
This is based on a linear correlation between surface area
of relatively inert particles and inflammatory response
measured by the total number of neutrophils in rats. Thus,
the genotoxic effects of PM can either be directly due to
surface properties of the particles or due to ROS released
by the inflammatory process. I will discuss inflammatory and
genotoxic effects of nanoparticles on the background of
results obtained in an ongoing project, Nanokem. The aims of
NanoKem are to identify and characterize the essential risks
caused by exposure to nanoparticles in the paint- and
lacquer industry.
Primary author
Dr
Anne Thoustrup Saber
(National Research Centre for the Working Environment, Copenhagen, Denmark)
