1, natural source
Natural sources include soil dust (containing oxide minerals and other components), sea salt (the second largest source of particulate matter, whose components are similar to seawater), plant pollen, spores, bacteria and so on.
2. Human resources
Man-made sources include fixed sources and mobile sources. Stationary sources include various fuel combustion sources, such as power generation, metallurgy, petroleum, chemistry, textile printing and dyeing, heating, cooking, coal and gas or lampblack.
Hazard: Fine particles are more harmful to human health, because the smaller the diameter, the deeper the part that enters the respiratory tract. Particles with a diameter of 10μm are usually deposited in the upper respiratory tract, and those below 2μm can penetrate bronchioles and alveoli. After fine particles enter the alveoli, they directly affect the ventilation function of the lungs, making the body vulnerable to hypoxia.
Extended data
preventive
1, filtering method
Including air conditioners, humidifiers, air purifiers, etc. The advantage is that the concentration of PM2.5 is obviously reduced, and the disadvantage is that the filter membrane needs to be cleaned or replaced.
2. Water adsorption method
Ultrasonic atomizer, indoor water curtain, pool, fish tank, etc. It can absorb hydrophilic PM2.5 in the air, but the disadvantage is that it increases humidity and hydrophobic PM2.5 cannot be effectively removed.
3. Plant absorption method
Plant leaves have a large surface area, which can absorb harmful gases and PM2.5 The advantage is that it can produce beneficial gases, but the disadvantage is that the absorption efficiency is low, and some plants can produce harmful gases.
Starting from 20 1 1, 1, 1, the Method for Determining the Weight of Ambient Air PM 10 and PM2.5 issued by the Ministry of Environmental Protection came into effect.
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