As a reminder ....

... that this issue is still with us, three clips from web-based environment sites, all taken within a few-minute span.

1) Real time map of particulate pollution across the US. This map shows PM2.5, the smallest particulates which are most damaging to the lungs:

2) EPA explanation of what the color-coding means.

3) What today's real-time monitoring of PM2.5 in Beijing shows. (Background here.) Note that the EPA charts have no reading or category for levels above 300, like the current 311 in Beijing.

This article available online at:

http://www.theatlantic.com/technology/archive/2009/05/as-a-reminder/18186/