Two Chinese entrepreneurs became billionaires on Tuesday as their companies rose to records on the prospect of new pollution laws after a Chinese documentary similar to “An Inconvenient Truth” sparked interest in environmentalism.

Zhang Kaiyuan, chairman of Beijing SPC Environment Protection Tech Co., has a net worth of $1.1 billion, while Ao Xiaoqiang, chairman of Beijing SDL Technology Co., has a $1.2 billion fortune, according to the Bloomberg Billionaires Index. Both companies are based in Beijing.

China’s annual meeting of the National People’s Congress, which begins March 5 in the capital, is expected to set government policies for the year on issues such as pollution. “Under the Dome,” a Chinese film investigating the fallout of the country’s poor air quality, drew millions of viewers over the weekend, putting a renewed spotlight on the issue ahead of the gathering of lawmakers.

“Every year during the National People’s Congress, environmental protection is a heated topic,” said Lai Shensheng, Shanghai-based environment analyst at Capital Securities Corp. “The inflow of capital is especially strong this year because of the huge reaction brought by the documentary.”

Best Performer

SPC Environment Protection, which builds so-called flue gas desulfuration to contain sulfur dioxide in thermal power plants, slumped 3 percent to 36.24 yuan at the Shenzhen close on Wednesday, retreating from a new high on Tuesday. SDL Technology, which makes equipment that tracks pollution levels, advanced by the 10 percent daily limit for two days before declining 1.7 percent to 39.99 yuan in Shenzhen.

The Shenzhen Composite Index, which tracks shares on China’s smaller exchange, where both stocks are traded, climbed 17 percent this year in U.S. dollar terms, the best performer among key indexes in Asia. The two stocks climbed at least 30 percent in 2015.

The rally has produced more than half a dozen billionaires, including Zheng Xiaodong, chairman of Shanghai Tofflon Science & Technology Co. Based on his 63 percent stake in Tofflon Science and cash holdings, Zheng’s net worth exceeded $1 billion after shares of the maker of vacuum freeze-drying equipment for pharmaceutical companies jumped to a record at the close in Shenzhen on Wednesday.

The annual meeting will probably lead to new policies to address air pollution, “including the boost of new energy vehicles,” analysts at Credit Suisse Group AG wrote in a research note.

‘Great Concern’

“Under the Dome” was released online by former China Central Television reporter Chai Jing, and was played at least 21 million times on video-sharing site Youku.com. The documentary was compared with “An Inconvenient Truth,” former U.S. Vice President Al Gore’s Oscar-winning documentary on global warming.

Chai said in the documentary she became afraid of pollution after her baby daughter had a benign tumor removed soon after she was born. The filmmaker also displayed pollutant charts and footage of doctors removing blackened lymph nodes from a lung-cancer patient who didn’t smoke.

“The environment has become a topic of great concern in China,” Lai from Capital Securities said. “People also expect that the government will do more in terms of environmental protection, which will benefit both companies.