Haze caused by fine particles is even more harmful to human health than sandstorms. Particles with a particle size of more than 10 microns will be blocked out of the human nose; particles with diameters between 2.5 microns and 10 microns can enter the upper respiratory tract, but some of them can be excreted through sputum, and will also be blocked by villi inside the nasal cavity, which is relatively less harmful to human health. Fine particles with a diameter of less than 2.5 microns will enter the bronchi, interfere with gas exchange in the lungs and cause diseases including asthma, bronchitis and cardiovascular diseases. These particles will also enter the blood, in which harmful gases, heavy metals and other dissolved in the blood, more harmful to human health.
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Different effects of particles with different particle sizes on human health