BEIJING, Sept. 14 -- China has cleaned up 1,790 crime cases involving environmental pollution from January to July this year, vice minister of environmental protection Wu Xiaoqing said Monday.

Addressing a symposium on environment and development, Wu said that since the new environmental protection law came into effect, the environmental protection authorities have been very busy.

The ministry conducted inspections and warned local officials with serious environmental problems in their area, Wu added.

The ministry has strengthened work on pollution. Among the 161 cities implementing new air quality standards in the first half of this year, 8.2 percent more days met the standard compared to the same period last year.

An action plan for water pollution has been fully implemented, while the authorities are devising action plan on soil pollution, Wu added.

The ministry has assisted local governments and centrally administered state-owned enterprises to make plans for emission cuts. Chemical oxygen demand and emissions of ammonia, sulfur dioxide and nitrous oxides dropped by 2.9 percent, 3.18 percent,4.63 percent, 8.8 percent year-on-year respectively in the first half of this year.