据北京市环境保护局相关负责人介绍，今年8月，北京的细颗粒物(PM2.5)平均浓度为35微克/立方米，创下近5年来的历史同期最佳纪录。
As the relevant responsible person of Beijing Environmental Protection Agency explained, the mean concentration of fine particulate matter (PM2.5) was 35 micrograms per cubic meter in Beijing in August of this year, which created the best record for the same period in history of the recent five years.