Large companies in South Korea have more than halved their air pollutant emissions over the past five years amid the government's anti-coal policies, a corporate tracker said Wednesday.

Air pollutant emissions by 166 plants of 77 large businesses came to 139,112 tons in 2020, down 56 percent from 316,013 five years earlier, according to CEO Score.

The environment ministry designates seven materials -- nitrogen oxide, dust, sulfur oxide, hydrogen fluoride, ammonia, carbon monoxide and hydrogen chloride -- as air pollutants and requires firms to measure their emissions by installing telemonitoring systems.

Those 77 companies have telemonitoring systems and belong to the country's top 500 businesses by sales.

CEO Score said their air pollutant emissions decreased the most, or 57,425 tons, from 2019 to 2020, amid government policies to cut dependence on coal for energy and a rising corporate drive to embrace environmental, social and governance management.

South Korea has been seeking to reduce the operation of coal-fired power plants in an effort to cut air pollution.

Korea South-East Power Co. has cut the largest amount over the past five years with 34,369 tons, with four other state power plants making the top-five list.

Among private companies, South Korea's No. 2 steelmaker, Hyundai Steel Co., ranked first by cutting 12,150 tons, followed by the second-largest oil refiner GS Caltex Corp. with 7,451 tons and major builder Ssangyong C&E Co. with 6,891 tons.

Bucking the trend, meanwhile, 15 out of the 77 corporations have increased their air pollutant emissions over the last five years, according to the corporate tracker. (Yonhap)