China’s capital city of Beijing was affected by dense sandstorms that severely affected visibility on Wednesday, shrouding buildings and roads in a thick blanket of dust.

The city, home to more than 21 million people, was issued a yellow sandstorm warning after experiencing sand and dust storms over the past several days, causing pollution levels to drastically increase.

Residents interviewed by Reuters said the adverse weather mostly did not hamper their daily routine, apart from the smell of dust on the subway and sand left on their clothes.

Beijing on Wednesday recorded an air quality index of 500, pushing the pollution level to 6—considered very hazardous to human health, according to the Beijing Ecological Environment Monitoring Center. The city faces regular sandstorms during March and April because of its proximity to the massive Gobi desert, as well as deforestation throughout northern China.