Shanghai ranks 48th among the 74 Chinese cities that adopted a new national air quality monitoring system last year, with the city’s annual PM2.5 density nearly double the national standard, according to a survey released yesterday.

Beijing came 13th in the list of cities with the worst air.

Shanghai’s annual average PM2.5 density was 60.7 micrograms per square meter last year, compared to the national standard of 35, environmental organization Greenpeace reported.

PM2.5 refers to airborne particles smaller than 2.5 micrometers in diameter that are the cause of urban smog and hazardous to health.

Greenpeace said that, in December, Shanghai’s PM2.5 density peaked at 421 micrograms per square meter, five times the daily standard of 75.

The Greenpeace report was based on data from China’s Environmental Protection Ministry website as well as environmental protection bureaus in the 74 cities.

The Yangtze River Delta region has seen increasingly severe air pollution in recent years that has affected the air quality in Shanghai.

Ten cities among 13 monitoring data in Shanghai’s neighboring province to the north, Jiangsu, recorded double the national annual standard for PM2.5, while nearly all the cities in Zhejiang Province, to Shanghai’s south, exceeded the standard.

In December, when the PM2.5 reading was at its peak in Shanghai, it was four times the standard in Zhejiang’s capital of Hangzhou and Jiangsu’s Nanjing, according to the Greenpeace.

“Some 20 percent of the PM2.5 pollution in Shanghai is from other provinces,” said Zhang Quan, Shanghai Environmental Protection Bureau director.

Vehicle and factory emissions accounted for 50 percent of the city’s pollution, followed by dust from construction sites (10.5 percent), power stations (7.3 percent) and straw burning (10 percent).

“The Chinese government must take emergency measures to curb nationwide air pollution,” Greenpeace said.

Some 92 percent of Chinese cities failed to reach the national standard in 2013, with 32 of them double the national standard while the top 10 were three times the standard.

North Chinese cities, especially those in Hebei Province, suffered the most serious pollution. Seven of the top 10 most polluted cities are in Hebei, led by Xingtai and Shijiazhuang. Both are important industrial cities.

Xingtai’s annual PM2.5 density reached 155.2 micrograms per square meter.

The air in China’s central and west cities, such as Xi’an in Shaanxi Province, Zhenzhou in Henan and Wuhan in Hebei, was also highly polluted last year, Greenpeace said.

China is to spend 5 billion yuan (US$818 million) to curb air pollution in north China and aims to slash PM2.5 density by 25 percent in the region within five years.

The fund, mainly to reward effective measures taken by regional governments, will be used to improve the air in Beijing and Tianjin, Inner Mongolia Autonomous Region and Hebei, Shanxi and Shandong provinces, according to the Ministry of Finance.

Hebei will be one of the campaign’s major targets.

Haikou in Hainan Island had the best air quality among the 74 cities, with an annual PM2.5 density of 25.6, followed by Lhasa in Tibet and Xiamen in southeast Fujian Province.