Why should we care about nanoparticles?

Nanoparticles are all around us all the time, and they are in us, too, because we breathe them.

Post-industrial "clean" urban air contains some 10'000 nanoparticles per ccm.

With every breath we take, about one out of three particles is deposited in our lungs. We have not developed any biological mechanism to protect us against the tiny intruders because on an evolutionary time scale, nanoparticles in such high concentrations are a completely new phenomenon.

Once deposited in the human organism, solid insoluble nanoparticles cause a multitude of health effects. While the exact mechanisms by which they affect our health are still subject to intense research, it is clear what they result in:
• increased mortality and morbidity,
• cardiovascular disease, • asthma,
• lung diseases and some more
• unspecific symptoms.
One of the largest ongoing nanoparticle inhalation experiments of mankind can be observed almost any time anywhere, although few of us are aware of it.

Cigarette smoking, that is inhalation of high numbers of combustion
generated nanoparticles, is known to kill people by the million.

Macrophagen ausgesetzt Polystyren-Teilchen unterschiedlicher Größe :
Die Nano-Partikel dringen in die Zelle ein

Makrophagen gehören zu den Fresszellen (Phagozyten) und sind als Leukozyten (weiße Blutkörperchen)
Zellen des Immunsystems. Sie dienen der Beseitigung von Mikroorganismen durch Phagozytose
und stellen stammesgeschichtlich (phylogenetisch) die vermutlich ältesten
Vermittler der angeborenen Immunabwehr dar. So sind Makrophagen-artige
Zellen in der Taufliege Drosophila und sogar in Pflanzen identifiziert worden (Quelle : Wikipedia)