A January temperature inversion over China has caused the air to stagnate and emissions of air pollutants to concentrate, especially over urban areas like Beijing. The air is so bad that it has forced the Chinese government to allow its media to agitate for pollution controls.
The air pollutant receiving the most media attention is fine particulate matter — soot and dust, or “PM2.5” in EPA-speak.
U.S. communities are out of daily compliance with EPA regulatory standards if local PM2.5 levels exceed 35 millionths of a gram (micrograms) per cubic meter of air in a 24-hour period. Communities are out of annual compliance with EPA standards if their average daily PM2.5 level exceeds 12 micrograms per cubic meter. This latter standard was just tightened from 15 micrograms per cubic meter in December.
As a practical matter, the average level of PM2.5 in U.S. air is about 10 micrograms per cubic meter, and the EPA standards are hardly ever exceeded in the vast majority of the country. Nonetheless, the agency’s justification for such strict standards is its assertion that PM2.5 kills people — a lot of them.
Read more at The Washington Times. By Steve Milloy.