The size of particles is important when:
inhaled into airways
- and once inhaled particles become deposited in organs.
- Larger particles (greater than 10 microns ) are generally filtered in the nose and throat and cause no problems.
- Particulate matter but that is less than 10 microns - also known as PM 10 called - can settle in the bronchi and lungs and cause health problems .
The 10-micron size here represents no strict boundary between respirable and non-respirable particles, but is a value to the various regulatory agencies have agreed worldwide.
- Similarly tend particles smaller than 2.5 microns (PM 2.5 ) to penetrate into the gas exchange region of the lung.
- A study, published in the Journal of the American Medical Association, shows that PM leads 2.5 to high deposits in arteries. This vascular inflammation and atherosclerosis are favored, ie hardening of the arteries, which can lead to heart attacks and other cardiovascular problems.
- Very small particles ( <0.1 micron ) can pass through the lungs and even invade other organs.
These particles, with less than 0.1 microns in diameter, can act on the cardiovascular system is still destructive.
- There is evidence that traverse particles that are smaller than 0.1 microns, cell membranes and can migrate to other organs including the brain.
It has also been pointed out that particulate matter can cause similar brain damage, such as Alzheimer's - disease.
- Particles of modern diesel engines (commonly referred to as diesel particulate matter, or DPM) is normally in the order of 0.1 micron.
In addition, these soot particles are absorbed carcinogenic components on their surface, such as benzopyrene .
It is clear that the legislative limits for engines, which are mainly related to the ejected mass, not the right measure for the health risks are.
