An investigation by the Ministry of Environmental Protection has uncovered numerous violations of emission standards by a large number of high-polluting industries in China.

Emission monitoring devices in many factories are not even providing reliable data about pollution, xinhuanet.com reported on Wednesday.

The ministry launched a week-long campaign to investigate the emission behavior of industries in 12 cities, including Beijing, Tianjin, Shijiazhuang, Tangshan, Langfang, and Taiyuan.

Over 60 industries in Beijing, Tianjin, Xingtai, Shijiazhuang, Dezhou and Zhengzhou have been exposed for violating emission standards, and a total of 34 polluting factories were reported in Tangshan.

Most of the blacklisted high-polluting enterprises are related to cement, coking, and steel.

Some of these polluters refused to stop operations even after they had received closure notices from local governments.

There are also some industries that refuse to apply desulfurization facilities to their machines.

At a chemical plant in Zhengding county of Shijiazhuang, emission monitoring equipment did not have desulfurization capability.

An employee at the environmental department found that monitoring equipment at some factories couldn't detect pollution even when there was sulfur-containing gas being released.

Extensive economic growth is the major reason behind the severe smog shrouding cities in China. Though China's GDP accounts for 10.48 percent of the world's total, its economic development takes up 60 percent of the cement, 49 percent of the steel, and 20.3 percent of the energy globally, said Chai Fahe, vice president of the China Research Academy of Environmental Science.

To better control pollution and improve air quality, governments should accelerate legislation and increase law-breaking punishments for polluters, Chai added.