BEIJING — Through the last four decades, China has achieved breathtaking economic growth at the cost of smoggy skies, fetid streams and lakes of dying fish.

Now China is undertaking one of its most extensive efforts yet to crack down on corporate polluters, an effort that could be felt economically and in world markets.

Cities across China have stepped up sending squads of inspectors to steel mills, coal-fired power plants and other businesses, and ordered offenders to clean up their operations or risk being shut down. On Aug. 21, the environmental authorities ordered more than two dozen cities in northern China, including many main steel production centers, to reduce air pollution by 15 percent this winter.

Even tougher measures will be coming, Li Ganjie, China’s minister for environmental protection, said Monday at a news conference held in conjunction with the Communist Party congress, a twice-per-decade event at which the party selects new leaders to tackle its problems.