China National Environment Monitor Center (CNEMC) workers inspect PM2.5 - airborne pollutants smaller than 2.5 microns in diameter - monitoring equipment in Beijing on Jan 4, 2012. The measuring of PM 2.5 and ozone density is scheduled to be fully implemented in China nationwide by 2016, with pilot projects conducted ahead of the national deadline in cities and municipalities in the Beijing-Tianjin-Hebei region, Yangtze River Delta and Pearl River Delta in 2012, according to the Ministry of Environmental Protection. [Photo/CFP]