SHENZHEN experienced 24 days of haze in the third quarter this year, 13 more than for the same period in 2010, according to the quarterly environmental report released at the weekend.

In a typical haze, visibility is less than 10 kilometers and the relative humidity is lower than 95 percent.

The environmental protection bureau attributed the haze to minimal precipitation in the third quarter when there was 455 millimeters of rain, a 45 percent decrease on average, according to the report.

Despite the increase in the number of hazy days, the report said the whole of the third quarter had “good” air quality.

The bureau said there was no national air quality standard for haze, which was a term used by meteorologists to describe PM2.5 which refers to inhalable particles less than 2.5 micrometers.

The bureau said that, although it did not take PM2.5 into consideration when assessing the environment, it had been monitoring PM2.5.

There are 18 environmental monitoring stations in Shenzhen capable of monitoring PM2.5, the bureau said. Shenzhen began monitoring for PM2.5 in 2007.

However, the bureau said it would not release the results until the environment ministry set a standard.

According to the report, 11 companies were fined between 100,000 yuan and 150,000 yuan in the third quarter.

The companies had either failed to undergo environmental assessments for construction projects or discharged excessive wastewater.

(Li Hao)