Average standard value of air quality grade PM2.5 hours:
Excellent 35 μ ug)/ m3
Good 35~75 μ g/m3
The light pollution is 75~ 1 15 μ ug)/ m3.
Moderate pollution 1 15~ 150 μ ug)/ m3.
The heavy pollution is 150~250 μ ug)/ m3.
Serious pollution of 250 and above micrograms (ug)/ cubic meter.
Extended data:
Main danger
Although fine particles are only a few components in the earth's atmosphere, they have an important impact on air quality and visibility. Compared with atmospheric coarse particles, fine particles are small in particle size, rich in a large number of toxic and harmful substances, stay in the atmosphere for a long time and have a long transportation distance, which has a great impact on human health and atmospheric environmental quality. Research shows that the smaller the particles, the greater the harm to human health. Fine particles can float far away, so the influence range is large.
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.
References:
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