Policies to improve the Shanghai's air quality will become even stricter following the World Expo, according to environmental protection watchdogs.

Existing initiatives to curb the number of construction projects downtown and control hay burning during the Expo will remain in practice, officials said, while joint efforts between Shanghai local authorities and counterparts in neighboring provinces to control air quality will be reinforced.

City officials said they want at least 90 percent of days after the event to meet the standard of excellent or good air quality - the top two of a five-level measurement.

The city has set a record this year with air quality on 96.3 percent of days by September and 98.7 percent of days since May 1 marked as excellent or good quality.

In 2009, some 91.5 percent of days in Shanghai met excellent or good standards.

This was the first time that the scoring exceeded 90 percent.

Officials from the Shanghai Environmental Protection Bureau said the city is working on the 12th five-year plan on environmental protection, which will be introduced next year.

Many initiatives introduced during the World Expo and which proved effective will be adopted as routine measures to help ensure better air quality.

Officials said they want to continue the joint monitoring and administration that was established with provinces of Zhejiang and Jiangsu before the Expo for regional air quality management. This seems to be very effective, they said.

Shanghai's environmental protection facilities launched vehicle emission checks at the major entrances to the city and parking lots around the Expo site.

As a result of these checks, 658 vehicles from other provinces with unacceptable emissions were detected and reported to authorities.

Meanwhile, the Yangtze River Delta air quality monitoring network, which consists of 53 automatic monitoring stations in Shanghai and the neighboring provinces of Zhejiang and Jiangsu, has been collecting data for real-time air quality supervision and providing 48-hour forecasts.

Whenever the possibility of a highly polluted day is forecast, the network rolls out emergency policies to control the emission of pollutants from big plants in Shanghai and neighboring regions.

Three such days were forecast, to date, during the Expo and measures taken in time to prevent bad air quality, the bureau said.