![Groups push for standards on PM2.5 anti-smog masks amid concern over fakes | South China Morning Post Groups push for standards on PM2.5 anti-smog masks amid concern over fakes | South China Morning Post](https://cdn1.i-scmp.com/sites/default/files/2014/02/27/china-pollution_pek701.jpg)
Groups push for standards on PM2.5 anti-smog masks amid concern over fakes | South China Morning Post
![Rooftop sensors on U.S. embassies are warning the world about 'crazy bad' air pollution | Science | AAAS Rooftop sensors on U.S. embassies are warning the world about 'crazy bad' air pollution | Science | AAAS](https://www.science.org/do/10.1126/science.aat9260/abs/ca_0420NID_Pollution_Beijing_online.jpg)
Rooftop sensors on U.S. embassies are warning the world about 'crazy bad' air pollution | Science | AAAS
![Pollutionwatch: do face masks really prevent the ill effects of pollution? | Air pollution | The Guardian Pollutionwatch: do face masks really prevent the ill effects of pollution? | Air pollution | The Guardian](https://i.guim.co.uk/img/media/23ebff09269888bec1e21dd2d1fd67a159bbe4ad/0_267_5229_3137/master/5229.jpg?width=1200&height=1200&quality=85&auto=format&fit=crop&s=7d07eb44ee14a650e03ca692d30c9001)
Pollutionwatch: do face masks really prevent the ill effects of pollution? | Air pollution | The Guardian
![Chinese Tourists Wearing Face Masks Air Pollution Visit Tiananmen Square – Stock Editorial Photo © ChinaImages #234219762 Chinese Tourists Wearing Face Masks Air Pollution Visit Tiananmen Square – Stock Editorial Photo © ChinaImages #234219762](https://st4.depositphotos.com/21607914/23421/i/1600/depositphotos_234219762-stock-photo-chinese-tourists-wearing-face-masks.jpg)
Chinese Tourists Wearing Face Masks Air Pollution Visit Tiananmen Square – Stock Editorial Photo © ChinaImages #234219762
![Beijing, China. 25th Dec, 2015. Students wearing masks walk on a smog-shrouded street for a school event in Beijing, Dec. 25, 2015. An orange alarm has been issued to alert smog and Beijing, China. 25th Dec, 2015. Students wearing masks walk on a smog-shrouded street for a school event in Beijing, Dec. 25, 2015. An orange alarm has been issued to alert smog and](https://c8.alamy.com/comp/FAA9DR/beijing-china-25th-dec-2015-students-wearing-masks-walk-on-a-smog-FAA9DR.jpg)