The smog-filled Beijing-Tianjin-Hebei region has seen improvement in combating particulate pollution, such as PM2.5, since 2013, but faces worsening ground-level ozone pollution during the summers, a challenge many developed countries share, a new report from Peking University said.
一份来自北京大学的最新报告称，受雾霾困扰的京津冀地区，自2013年以来在对抗诸如PM2.5等微尘污染方面取得了成效，但却在夏季面临日益严重的地面臭氧污染。臭氧污染是许多发达国家所面临的问题。
The 13 cities in the Beijing-Tianjin-Hebei region last year saw the annual average concentration of ground-level ozone increase by 13.1%, compared with the level in 2013, the report said.
报告称，与2013年相比，去年京津冀地区的13个城市的地面臭氧年均浓度上升了13.1%。
The report was conducted by the Center for Statistical Science and the Guanghua School of Management, both based at Peking University, using data released from the 73 State-controlled air quality monitoring stations and 25 meteorological stations in the region between March 2013 and May 2015.
该报告是由北京大学统计科学中心和光华管理学院发起的，使用了从2013年3月至2015年5月期间，该地区73个国家控制的空气质量监测站和25个气象站发布的数据。

"The analysis has clearly showed the sharp decline of the major airborne pollutants since 2013, especially of particulate matter, because a package of strong control measure initiated in past years works," Chen Songxi, director of the statistics center and survey leader said.
该项调查的带头人、统计中心的负责人陈松蹊表示：“这一分析清楚地表明，由于过去几年所开展的一项强有力的控制措施，自2013年以来，主要空气污染物的急剧下降，尤其是颗粒物。”
But among other major pollutants, ground-level ozone concentration has increased in the 13 cities between 2013 and 2016, the report said.
不过该报告指出，在2013年至2016年间，在其他主要污染物中，该地区13个城市的地面臭氧浓度有所上升。
"In summers, this invisible oxygen pollution worsened, and governments should set reduction targets to control it, like they did in combating PM2.5," said Chen.
陈松蹊说道；“在夏天，这种无形的氧气污染恶化了，政府应该制定减排目标来控制它，就像他们在与pm2.5的斗争中所做的那样。”
High ozone concentration at ground level could lead to breathing problems and lung diseases, the World Health Organization has said.
世界卫生组织称，地面臭氧浓度高或导致呼吸问题和肺部疾病。