(ECNS) -- Despite China's massive efforts to tackle air pollution, one key source of pollutants -- nitrogen oxides (NOx) and particulate matter in diesel exhaust fumes -- have not been sufficiently addressed, according to experts.
Bao Xiaofen, director of the Ministry of Environmental Protection Vehicle Emission Control Center, said China has introduced strict controls on gasoline-fueled vehicles, with policies even harsher than in some Western countries, but automobiles with diesel engines are still a big problem.
His comments were supported by a report from Clean Air Asia, an international NGO, which said the culprits of toxic haze are industrial and automobile pollution, but China has overlooked diesel-fueled vehicles.
Diesel vehicles accounted for 12.6 percent of all cars across China in 2015, but they contributed 69 percent of nitrogen oxides (3.72 million tons) and 99 percent of particulate matter (536,000 tons) in emissions.
Professor He Kebin from the School of Environment at Tsinghua University said particulate matter from diesel engine exhausts is smaller than the most-talked about PM 2.5 and also carries heavy metals, making it more harmful to health.
He urged more measures to control emissions from ships, planes, agricultural facilities and industrial machinery powered by diesel fuel.
Tian Jing, in charge of the environmental NGO "Good Air Defenders", said public reports often neglect the influence of exhaust fumes from diesel vehicles, adding that China's current law on air protection makes only general requirements on heavy-duty diesel engines, so in practice the use of heavily polluting vehicles is widespread.
A survey by the group conducted over six months showed diesel exhaust fumes is an important source of pollution, according to Science and Technology Daily.
China's smog-hit capital Beijing plans to slash coal consumption by a further 30 percent in 2017 as part of its efforts to combat air pollution. Besides, from next month, around 300,000 high-polluting vehicles will be restricted from entering the city.
