过去三年，北京市PM2.5中对人体有害的金属毒素的比重有所下降，专家称北京市的雾霾防治措施取得了初步成效。

　　The ratios of three carcinogenic heavy metals – arsenic, lead and cadmium - in the PM2.5 of the city's air have dropped by 85.9%, 48.9% and 40.7% respectively, according to a report jointly released by Pan Xiaochuan, a professor from the School of Public Health with Peking University, and an environmental organization.

　　北京大学公共卫生学院教授潘小川与某环境组织共同发布的报告称，北京大气PM2.5中砷、铅和镉三种致癌重金属元素的比重分别下降了85.9%、48.9%和40.7%。

　　报告指出 北京雾霾毒性已经有所下降

　　Beijing has closed three coal power plants since 2014, and the density of the sulfur dioxide discharged from coal burning dropped 49 percent compared with the data from 2013.

　　北京市自2014年起关闭了三家燃煤发电厂，燃煤排放的二氧化硫的密度与2013年的数据相比下降了49%。

　　Dong Liansai, director of the environmental organization, said that the decrease of the density of arsenic and sulfur dioxide shows the government's measures to cut air pollution are working.

　　该环保组织的董连赛主任表示，砷和二氧化硫密度的下降表明政府减少空气污染的措施已经起到了效果。

　　However, Dong noted that there are still other carcinogenic substances in the PM 2.5 that are harmful to human health.

　　不过董连赛指出，PM2.5中仍然有其他对人体健康有害的致癌物质。

　　But Net users were not so impressed by the decrease of hazardous substances in the air with some mocking that the smog has now become "environmental-friendly."

　　但网友却并没有对空气中有害物质的减少留下深刻的印象，其中一些人嘲讽称，雾霾现在已经变得环保了。