近期,我国北方地区出现多日的雾霾天气,空气质量十分糟糕。因此一个名词PM2.5高频率出现在各大媒体上。到底PM2.5是什么意思?其对民众的健康是否造成危害呢?PM2.5是指大气中直径小于或等于2.5微米的颗粒物,也称为可入肺颗粒物。它的直径还不到人的头发丝粗细的1/20。虽然PM2.5只是地球大气成分中含量很少的组分,但它对空气质量和能见度等有重要的影响。与较粗的大气颗粒物相比,PM2.5粒径小,富含大量的有毒、有害物质且在大气中 Recently, there have been many days of fog and haze in the northern part of our country, and the air quality is very poor. Therefore, a noun PM2.5 high frequency appeared in various media. PM2.5 in the end is what is the meaning of its public health is causing harm? PM2.5 is less than or equal to 2.5 microns in the atmosphere of particulate matter, also known as particulate matter into the lungs. Its diameter is less than 1/20 of the thickness of a human hair. Although PM2.5 is only a very small component of the earth’s atmosphere, it has important implications for air quality and visibility. Compared with the coarse atmospheric particles, PM2.5 particle size is small, rich in a large number of toxic and hazardous substances in the atmosphere