By Bloomberg News - 2013-01-30T22:00:00Z Beijing’s air, which has exceeded the World Health Organization’s “healthy” limit every day this year, is similar to that in an airport smoking lounge. The CHART OF THE DAY shows Beijing’s daily peak and average concentrations of PM2.5, the airborne particulate matter that raises risks for lung and heart diseases, as measured by the U.S. Embassy. The 2013 daily average was 194 micrograms per cubic meter, with an intraday peak of 886 on Jan. 12, the data show. By contrast, PM2.5 levels averaged 166.6 in 16