China on Thursday passed the first amendment to its environment protection law in 25 years, imposing tougher penalties on polluters after the government called for a "war" on pollution.

The changes approved by the standing committee of the National People's Congress (NPC), China's rubberstamp parliament, take effect on January 1, 2015 and come amid growing public discontent over pollution.

The revised law imposes "harsher punishments (for) environmental wrongdoing, and has specific articles and provisions on tackling smog, making citizen's more aware of environmental protection and protecting whistleblowers", the state-run Xinhua news agency said.

The law also stipulates up to 15 days' detention for officials in enterprises that, among other violations, avoid "environmental impact assessments and refuse to suspend production after being issued a ban", Xinhua said.

"The new law stipulates that enterprises will be named and shamed for breaking environmental protection laws," it said.

China's decades-long economic boom has brought rising environmental problems, with large parts of the country repeatedly blanketed in thick smog and both waterways and land polluted.

Pollution has emerged as a driver of discontent with the government, sparking occasional protests.

Xinhua said the amendment marked "the first change to the legislation in 25 years".

The amendment approved Thursday -- which also called on citizens to adopt a "low-carbon and frugal lifestyle" -- came after Premier Li Keqiang last month vowed to declare a "war" against pollution.

Sixty percent of underground water in China which is officially monitored is too polluted to drink directly, according to state media, underlining the country's grave environmental problems.

China's environment ministry recently estimated that 16 percent of the country's land area was polluted, with nearly one fifth of farmland tainted by inorganic elements such as cadmium.

Air quality was below national standards in almost all China's major cities last year, a top environment official said last month, with only three out of the 74 cities monitored by the government meeting a new air quality standard.