Beijing pollution 'worst on record'

Air quality in Beijing was the "worst on record" this weekend, according to environmentalists.

The city's pollution monitoring centre has warned residents to stay indoors with pollution 30-45 times above recommended safety levels.

The Chinese capital, home to around 20 million people, has been wrapped in thick smog since Friday, reducing visibility and disrupting traffic. Such pollution has been identified as a major cause of asthma and respiratory diseases.

Data posted today by the monitoring centre showed particulate matter measuring less than 2.5 micrometres in diameter (PM2.5) had reached more than 600 micrograms per square metre at some monitoring stations in Beijing, and was as high as 900 yesterday evening.

The recommended daily level for PM2.5 is 20, according to the World Health Organisation, while the US’s Environmental Protection Agency advises anything greater than 300 would trigger a health warning of “emergency conditions” with the entire population likely affected.

"This is really the worst on record not only from the official data but also from the monitoring data from the US embassy - some areas in (neighbouring) Hebei province are even worst than Beijing," said Zhou Rong, climate and energy campaigner at Greenpeace.

The Beijing Municipal Environmental Monitoring Centre said heavy pollution had been trapped by an area of low pressure, making it harder to disperse, and the conditions were likely to last another two days.