BEIJING – Scientists have found a new culprit contributing to China's notorious winter smog, and it has been able to sustain the significant improvement in air quality that Beijing and other northeastern cities experienced last winter.
Scientists from Harvard and two Chinese universities report that they are all in the same condition as they are.
In a report published in the journal Geophysical Research (19659002) China's efforts to reduce the haze have focused on reducing sulfur dioxide emissions. In China, the research suggests that the emissions of formaldehyde in vehicles and industrial refining can be reduced.
The easiest fixes on cars and trucks and fittings at fumes from escaping, he said. Reducing emissions from chemical and oil refineries, which are heavily concentrated in Tianjin, the coastal metropolis near Beijing, could have been a disproportionate impact, he said, but those could prove more difficult to enforce.
burning of coal, the cuts in the output of refineries could have been threatening China's growth.
When the Chinese Ministry of Ecology and Environment issued its annual guidelines for 28 cities in the northeast last month, it eased requirements for new cuts in steel mills, coking plants and other factories to shut down for several months.  Choking haze many times the safe levels recommended by the World Health Organization.
The concentration of PM 2.5, or particulate matter of a particular kind – has been blamed for as many as one million premature deaths a year.
The main Particulate matter in pollution in China has long been thought to be sulfate, a product of sulfur dioxide released by burning coal. But another sulfur molecule, hydroxymethane sulfonate, is also a significant contributor, according to the study, conducted by Tsinghua University in Beijing and the Harbin Institute of Technology in Harbin, the capital of China's northernmost province, Heilongjiang.
The molecule It is considered that the term "extreme air pollution events" has not yet been established.