One month into the Ministry of Environmental Protection's yearlong inspection of 28 northern cities — which in uncovering violations on an almost daily basis — companies are feeling the pressure to reduce pollution.

The cities that have received feedback have responded quickly and thoroughly, according to local officials and the bosses of the companies targeted in the campaign, which is focused on the Beijing-Tianjin-Hebei region.

Yuntaishan Cement's factory in Wuan, Hebei province, was ordered to halt production on April 9, just two days into the inspection, after it was found with raw materials piled outdoors and no way to prevent dust pollution.

The company was fined 120,000 yuan ($17,400) by the city's environmental protection bureau and given until the end of May to upgrade its equipment or remain shut down.

"The improvements to reduce emissions will cost about 2 million yuan, which is not a small investment,"said Zhang Xinchang, the plant's manager. "But now is not a time for bargaining.”

Compared with previous inspections, the city government is taking a tougher stance, Zhang added.

In fact, Guo Quansheng, Wuan's vice-mayor, said that based on the Yuntaishan case the Wuan authorities decided to launch a sweep of the city's 13 other cement factories. This resulted in three more being temporarily closed for pollution violations, while all were ordered to upgrade their equipment.

"The violations exposed in one plant became a warning for us to check the entire industry,"Gao said.

Cui Hongzhi, head of environmental protection for Handan, Hebei's second-largest city by land area, said government agencies covering the environment, economy and commerce have been given the responsibility of ensuring that problems identified by the ministry's inspection teams are fixed.

Handan has a large concentration of iron, steel, cement, and coking businesses. Between April 8 and 16, the city ordered 26 companies to reduce or suspend production, closed 14 companies permanently and issued fines totaling 25 million yuan, the ministry said.

Authorities said many problems have already been resolved in neighboring Xingtai. Si Guoliang, its environmental protection chief, said 158 of the 173 violations logged by inspectors had been addressed.

It's the first time such an intensive environmental inspection has continued without a break, as previous ones were only conducted on days with heavy smog, he said, adding that the authorities will visit the polluting companies frequently to guarantee the problems are completely solved.

"We will take it as an opportunity to reduce air pollution,"he said, adding that the city saw air quality worsen in the first two months of this year.

Ministry inspection teams were also scheduled to randomly check 30 percent of the companies found in violation in Xingtai before May 6 to see if corrective measures have been implemented well.

The ministry is publishing the violations found in the 28 cities every day, sending a strong signal that the central government is serious about reducing pollution.

"How to correct the pollution problem is also a priority in making the inspection work,"said Tian Weiyong, head of the ministry's monitoring department.

Cities that fail to deal with pollution issues will be punished by the ministry, Tian said — for example by having projects restricted and officials held accountable.

As of May 1, inspectors had checked 6,738 companies and exposed 4,570 violations in the 28 cities, of which 1,569 unregistered companies — whose operations are not authorized — were found with excessive emissions, according to the latest data from the ministry.