Particularly Bad: A Look at PM 2.5 Pollution

Beijing’s announcement that it will begin releasing hourly PM2.5 readings of the city’s pollution on January 23 is certainly good news, but the fervent response from newspapers and blogs seem a bit premature. We’ll get excited when Beijing begins reducing the pollution, not just telling us about it. If all the talk concerning PM 10 and 2.5, particulates and microns has you scratching your head, we’ve laid it out in our January Ecology feature.

Want an idea of how small these particles are that everyone talks about? PM10 refers to particulate matter with a diameter of 10 microns or less. These particulates primarily include dirt and dust created by construction or factories. PM2.5 refers to particulate matter with a diameter of 2.5 microns or less. These particulates originate primarily from combustion sources (i.e. emissions from motor vehicles, wood and coal burning, etc.).

Suspendable particles (ones that can hang in the air) are nearly half the width of a human hair, while PM10 particles are small enough to be inhaled into the lungs, and PM2.5 particles are small enough to get absorbed into the bloodstream. Long-term exposure risks to PM2.5 particulates include cancer and heart disease.

Click here to see the January issue of the Beijinger in full.