Very briefly, the atmospheric particles, well known as "PM" (Particulate Matter), is a very heterogeneous set of particles.
The classification provides a breakdown in three classes according to the diameter of individual particles:
- coarse : between 2.5 and 10 mM, the portion is coarser (one known as "PM10").
- end : between 0.1 and 2.5 mM, of intermediate size (the less famous "PM2.5").
- ultrafine : particle diameter less than 0.1 mM, very small.
What I do not know is that it is more dangerous than PM10, PM2.5, but!
The classification provides a breakdown in three classes according to the diameter of individual particles:
- coarse : between 2.5 and 10 mM, the portion is coarser (one known as "PM10").
- end : between 0.1 and 2.5 mM, of intermediate size (the less famous "PM2.5").
- ultrafine : particle diameter less than 0.1 mM, very small.
What I do not know is that it is more dangerous than PM10, PM2.5, but!
The larger particles, in fact, are trapped in the first part of the respiratory system (nose, trachea, bronchi), while those actually respirable, ie, those who arrive in the alveoli, are the finest. And 'here pursuing their toxic action is taking place here the exchange of oxygen and carbon dioxide.
But what is a toxic effect? Must be a short introduction: on the surface of these particles are a true infinity of substances, both natural (crustal elements, pollen, bacteria ,...), both anthropogenic (pollutants from traffic, PAHs - polycyclic aromatic hydrocarbons, nitrates, sulfates ,...). Understand that if highly toxic elements reaching the alveoli ... the damage is inevitable.
What happens at the cellular level, shown in numerous studies, is the breaking cell membranes: both outer membranes (ie, bounding the "borders" of the cells, biologists will forgive me but my purpose here is not scientifically describe the cellular morphology) and the membranes of organelles within cells. The main targets are in fact the mitochondria, which in very simple words are the power plants of cells: whether their ability to provide power fails, all the basic processes are compromised and the cell dies.
The question that arises is ... why, today, there are still no laws regulating the emissions of PM2.5? And yet, because the newspapers and on television always insist on talking only and only when the fraction of PM10 PM2.5 is more harmful?
Probably not depress us, that's why.
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