What does pm2.5 mean? Can't read the weather forecast!

PM2.5 refers to particles with a diameter less than or equal to 2.5 microns in the atmosphere, also known as particles that can enter the lungs. Although PM2.5 is only a small part of the composition of the earth's atmosphere, it has an important impact on air quality and visibility. PM2.5 has a small particle size, is rich in a large number of toxic and harmful substances, stays in the atmosphere for a long time and has a long transportation distance, so it has a great impact on human health and atmospheric environmental quality. 20 12 In February, the State Council agreed to release the newly revised Ambient Air Quality Standard, adding the monitoring indicators of PM2.5 On September 9, 20 12, the monitoring center of Beijing Environmental Protection Bureau said that the new air quality release platform 20 13 1 was launched. On June 6th, at 20 12 and 10, the trial operation data of 35 PM2.5 monitoring stations in Beijing were all released online.