Shanghai's PM2.5 density at 10-year low: report

Tian Shengjie
With PM2.5 density the lowest in 10 years, Shanghai is now working to enhance marine and coastal protection, building greater systems to manage seawater pollutants.
Tian Shengjie

A public service announcement for marine environmental protection was released by the city's ecology and environment bureau during Thursday's conference, ahead of World Oceans Day on June 8.

Shanghai's annual average PM2.5 density last year was 25 micrograms per cubic meter, the lowest in 10 years, the city's ecology and environment bureau said on Thursday.

A key indicator of air pollution, it has decreased 7.4 percent year on year, the authority said.

The annual average density of PM10 and nitrogen dioxide, two of the major air pollutants, have also seen a year-on-year decline of 9.3 percent and 22.9 percent, respectively.

But the ozone figures increased 13.1 percent to 164 micrograms per cubic meter, compared with that in 2021, because of the high temperatures, it said.

The data from the city's climate center shows that there were 50 days over 35 degrees Celsius last year, 29 days more than usual. The city suffered 7 days with over 40 degrees Celsius in 2022, which broke the record from the last 150 years.

Volatile organic compounds and nitrogen oxides formed by car exhaust can catalyze the ozone through high temperatures and strong sunlight.

The bureau also said the seawater quality in the city improved in 2022.

The area with first- and second-class water quality reached 34.6 percent of the city's total sea area, increasing 9.2 percentage points year on year. The water quality inferior to the fourth class was 44.2 percent, declining 16 percentage points year on year, it said.

According to the national standard of seawater quality, there are four classes. The first- and second-class seawater is suitable for marine fishery, biological reserve, fish farming, entertainment and industrial water related to human consumption. The third class is for general industrial water and coastal tourism, and the last class is for exploitation and port.

The development of the coastal region in Jinshan District along the Hangzhou Bay will be prioritized until 2025, said Tan Jing, an official at the bureau.

"It will become a showpiece of a coastal garden city where people can enjoy living, working and touring," she said.

With the initial plan deemed a success, the district and bureau are working on a plan for the development of all coastal garden cities in Shanghai.

"Last year, we also signed an agreement with the provinces of Zhejiang and Jiangsu for environmental protection in the coastal sea area of Hangzhou Bay," she said. "Seawater is fluid so the environmental care needs cooperation."

On this year's World Environment Day next Monday, many activities for environmental protection via television and photography exhibitions will be held. Part of the related places, including environmental monitor stations and sewage-treatment plants, and 39 education bases will be opened to the public for the day, the bureau said.

More information about the list of places, reservations, and times can be seen on the bureau's Wechat account (上海环境).

Special Reports