Four major air and water pollutants were reduced in the first half of 2015, as a majority of companies in major industries installed equipment to reduce emissions.

In the first six months, emissions of sulfur dioxide was reduced by 4.63 percent year-on-year to 9.89 million metric tons nationwide, and nitrogen oxide was reduced by 8.8 percent to 10.03 million tons, said Liu Bingjiang, chief pollutants emission official at the Ministry of Environmental Protection, on Sunday.

In water, chemical oxygen demand was reduced to 11,83 million tons, a year-on-year decrease of 2.9 percent; and ammonia nitrogen fell to 1.19 million tons, a decrease of 3.18 percent.

Many major polluting industries have cleaner plants. For example, 96 percent of thermal plants have installed equipment to reduce sulfur dioxide emissions, the ministry said.

The newly revised law on air pollution imposes strict controls to reduce the air pollution, especially from the companies with excessive emissions, said Vice-Minister Pan Yue.

In addition to the major pollutants, the law will also set emission limits on other pollutants and provide the ministry with solid legal support to take harsher enforcement measures, including suspension of the approval rights of local governments on projects if they fail to control emissions, Pan said.