Chinese state media said on Wednesday that high levels of pollution are expected to continue in Beijing and the surrounding region until mid-November.
Tens of millions of residents of the Chinese capital and its surrounding areas experienced some of the worst smog in months this week.
Concentrations of dangerous PM2.5 fine particles (less than 2.5 micrometers in diameter) were more than 20 times higher than World Health Organization (WHO) recommendations in Beijing on Wednesday, monitoring company IQAir said.
The Chinese capital is currently the third largest city in the world, the Swiss company said.
In response to the smog, authorities took measures to restrict the movement of high-polluting vehicles and urged residents to stay home.
The Beijing, Tianjin and Hebei regions are expected to experience “moderate” levels of pollution, well above recommendations and “severe and high” until mid-November, according to the state-run Beijing Daily newspaper.
More than 100 million people live in this region.
The forecast for the region is based on a joint analysis by China’s National Environmental Monitoring Center and local weather authorities across the country.
“The main pollutants (in the Beijing-Tianjin-Hebei region) are PM2.5 and PM10,” the report said.
According to the U.S. Environmental Protection Agency, these pollutants are linked to premature deaths in people with heart or lung disease, as well as a variety of respiratory and other health problems.
In Beijing, authorities issued a warning on Monday about the country’s second-highest level of pollution.
And in parts of Hebei, visibility is reduced to less than 50 meters. Authorities blamed “unfavorable weather conditions” for the extent of the pollution.
The Chinese capital declared a “war on pollution” in 2015 after winning the Winter Olympics. It closed dozens of coal-fired power plants and relocated heavy industry.
Although there have been improvements in recent years, air quality is still well below WHO standards. China is the world’s largest emitter of greenhouse gases that cause climate change, such as carbon dioxide.
The recent surge in permits for coal-fired power plants has heightened fears that China will back away from its goals of meeting emissions between 2026 and 2030 and achieving carbon neutrality by 2060.