SHENZHEN reported 17 more days with good air quality in the third quarter (Q3) than the same period last year, statistics from the Shenzhen Municipal Ecology and Environment Bureau showed Tuesday.

Between July and September, the overall Air Quality Index readings ranged between 19 and 139 in Shenzhen. A total of 70 days were recorded as Grade I, or Excellent, with readings between 0-50, 17 days more than the same period of last year.

The days that reached the top two grades, Grade I and II, totalled 87 days, 14.2 percentage points higher than the same period last year. The index readings of days recorded at Grade II range from 50 to 100.

The concentrations of nitrogen dioxide, inhalable particulate matters and ultra fine particles also dropped, except sulfur dioxide that increased by 1 microgram per cubic meter from the 5 micrograms per cubic meter in Q3 last year. The concentration of ozone decreased significantly to 124 micrograms per cubic meter, down 76 micrograms per cubic meter compared with Q3 last year.

The decrease of ozone concentration indicates reduction of secondary pollution because it was generated by nitrogen oxides and volatile organic compounds under high temperatures and strong sunlight, according to Xu Hongfan, a department director of the bureau.

In river treatment, the water quality of Maozhou River has been significantly increased.

Between July and September, the bureau handled 560 environment pollution cases with 22.42 million yuan (US$3.4 million) in penalties. Ten cases had been handed to police for suspected environment pollution crimes. 

(Han Ximin)