Shanghai's environmental bureau cited fewer than 3 percent of the companies that it investigated for pollution violations in January 2013, a high-ranking legislator said at a meeting Thursday.

The Shanghai Environmental Protection Bureau punished 1,284 of the 45,000 companies it investigated that month, issuing an average fine of 50,000 yuan ($8,235), said Ding Wei, a member of the Standing Committee of the Shanghai Municipal People's Congress (SMPC).

Ding, who spoke during the 10th Session of the Standing Committee of the 14th SMPC, brought up the data point to criticize the environmental bureau for going too easy on polluters as the city continues to suffer from severe levels of air pollution. 

The average level of the pollutant PM 2.5 was 60 micrograms per cubic meter in 2013, about 70 percent above the national limit, according to one committee member.

PM 2.5, which stands for particulate matter that is 2.5 micrometers or smaller in diameter, was primarily responsible for the city's air pollution this year. The pollutant is considered especially dangerous because the small size of the particulates allows them to lodge deeply in the lungs, where they can aggravate respiratory illnesses.

The environmental bureau issued its highest-level air pollution warning for the first time on December 6, after the hourly PM 2.5 level hit 602.5 micrograms per cubic meter at 1 pm, more than eight times the national limit.

Although the environmental protection bureau issued the Shanghai Clean Air Action Plan in October, which urged government agencies and companies to take measures to improve the city's air quality, the standing committee members said that bureau hasn't done enough to see that they followed through.

The environmental bureau said it would adjust its policies, but offered no details how it would do so.

Committee members also pointed out that the bureau was late in issuing air pollution warnings in early December.

The bureau promised to improve its forecasting capability and issue the alerts earlier.

The Shanghai Environmental Monitoring Center predicted Thursday that Shanghai's Air Quality Index (AQI) will range from 70 to 95 Friday, indicating moderate pollution.

The AQI stood at 279 at 9 pm Thursday, with the PM 2.5 level at 64.4 micrograms per cubic meter.

The PM 2.5 level had surpassed 400 micrograms per cubic meter earlier in the day.