颗粒物（PM），也称为颗粒污染，是进入到空气中的极小颗粒和液滴的复杂混合物。一旦吸入，这些颗粒会影响心脏和肺部，并对健康造成严重影响。 

Do you know what a particulate is?

Particulate matter (PM), also known as particle pollution, is a complex mixture of extremely small particles and liquid droplets that get into the air.  Once inhaled, these particles can affect the heart and lungs and cause serious health effects. #freshten#