On January 4th, the Beijing Municipal Environmental Protection Bureau published the 2015 Beijing Air Quality Report, which found the annual average PM2.5 concentration had dropped by 6.2 percent compared to the previous year, but is still 2.3 times the national standard. Beijing had 42 heavily-polluted days in 2015. Coal combustion at the regional level and local vehicle emissions are the key pollution sources.
(Source:21st Century Business Herald )
