In the past few years, lawyer Gao Mingqin had been reluctant to come to Beijing for business trips due to the lingering smog in the capital. But the situation has changed since 2017.

"Thanks to the country's greater efforts to fight pollution, I saw more blue skies and breathed cleaner air in the capital last year," said Gao, a deputy to the 13th National People's Congress, the top legislature.

Environmental protection has been a hot topic among legislators and political advisers attending the annual sessions of the NPC and the Chinese People's Political Consultative Conference National Committee over the past few years.

Gao said she believes a heated discussion at this year's sessions will involve how to ensure sustainable development of pollution controls.

"I'm looking forward to stronger determination from the government and more judicial measures to control pollution, such as to increase punishments for polluters," she said.

In the past five years, the NPC Standing Committee has adopted and revised about 20 laws and bills on environment and ecology, including the Water Pollution Prevention and Control Law, the Environmental Protection Law and the Air Pollution Prevention Law.

A draft law on soil pollution control and prevention, which aims to boost monitoring and clarifying supervision responsibilities, may also be adopted in the near future as lawmakers have reviewed it twice, in June and December. A draft law usually receives three reviews before being passed by the legislature.

"Environment-related legislation has been greatly enhanced since the 18th National Congress of the Communist Party of China in late 2012," said Zhang Guilong, a senior official on the NPC Standing Committee's Legal Affairs Commission.

The revised Environmental Protection Law, effective since 2015, is the law with the strictest punishments. Polluters face a fine ranging between 10,000 and 100,000 yuan ($1,576 to $15,765) a day if they do not stop emissions after being alerted, and there is no ceiling for the fine.

Last year, the country administratively punished 233,000 environmental violations, with the amount of fines reaching 11.58 billion yuan. "These figures are much bigger than those before the revised law," Zhang said.

Enforcement inspections on such laws also have been enhanced. From June to August, legislators were divided into five teams for 10 regions to check how the Solid Waste Control Law had been implemented. Zhang Dejiang, chairman of the NPC Standing Committee, made a law inspection report in November to the committee.

The move showed lawmakers' rising attention to problems often complained about in public, such as trash collection, experts said.

The legislature also has made it clear that environment-related regulations and rules issued by other authorities, such as local governments, will be placed under closer check this year to make sure they are all in line with laws at a higher level. If any improper articles are found, related departments will be urged to fix them as soon as possible.

Reviewing administrative rules, local laws and regulations, as well as judicial interpretations is a significant duty of the NPC Standing Committee, which has the duty and obligation to nullify documents that contradict the Constitution and laws.