Shanghai, China, Mar 15 (efe-epa).- Residents in Beijing Monday woke up to a city enveloped by a thick brown smog due to high pollution levels in recent days and a sandstorm from Mongolia.
The Beijing Meteorological Service issued a yellow alert for a sandstorm in the morning.
It warned that the dust was likely to last until the afternoon when winds would begin to dissipate it.
But the dust could return on Tuesday due to other air currents.
The authorities have asked the elderly, children, and people with respiratory diseases to stay indoors during the day.
The concentration of particulate matter PM10, for example, dust and ash, in the air reached almost 5,800 micrograms per cubic meter after 11 am.
At that time, the concentration of PM2.5 particles – considered the most harmful to health – in the air was 386 micrograms per cubic meter, well above the limit of 25 micrograms recommended by the World Health Organization.
This caused the city’s air quality index (AQI) to stand at an average level of 424 at that time.
The higher the AQI value, the greater the level of air pollution.
However, early in the morning, the index had exceeded 2,000 in some parts of the city.
Visibility also dropped to as low as 300 meters (984 feet) in some areas of the Chinese capital.
The Chinese government has been trying to fight desert sandstorms in the north of the country for years with the help of massive reforestation programs.
However, while this has managed to reduce their frequency, storms are still frequent every spring. EFE-EPA