Most near-surface ozone is produced by nitrogen oxides emitted by motor vehicles, power plants, coal-fired boilers and cement kilns under high-temperature illumination, plus volatile organic compounds (VOCs) emitted by motor vehicles and petrochemical industries and volatile organic solvents, both of which are generated under the catalysis of solar radiation.

Volatile organic compounds (VOCs) come from industrial production such as petrochemical industry, organic chemical industry, surface painting, packaging and printing, as well as daily life such as decoration, dry cleaning and catering, with scattered sources and great difficulty in control. Since the beginning of summer, the popular open-air barbecue has accelerated the production of ozone precursors. In addition, the exhaust gas from motor vehicles contains both nitrogen oxides and hydrocarbons, which is also an excellent condition for the formation of ozone.

like smog, the harm of ozone cannot be underestimated. Relevant research shows that when the ozone concentration reaches more than 211 μ g/m3, it will damage the central nervous system, causing headaches, chest tightness and decreased thinking ability.

Stimulate eyes, which reduces visual sensitivity and vision; Destroy vitamin E in the skin, and make the skin grow wrinkles and dark spots; Ozone will hinder the oxygen transmission function of blood and cause tissue hypoxia; Impairment of thyroid function and calcification of bones. In addition, ozone can also cause plant leaves to die, fall off, grow bleaching spots and inhibit growth, resulting in crop yield reduction.

Extended information:

Xiao Yu, a researcher at the Institute of Atmospheric Physics, Chinese Academy of Sciences, said that at an altitude of 11-51 kilometers from the ground, ozone can absorb ultraviolet rays, and it is a well-deserved "guardian of the earth". Once ozone reaches the near-surface layer about 11-111 meters from the ground, it will change into a terrible face and become a "health killer" of human beings, which should arouse the public and environmental protection departments.

Studies have shown that when the ozone concentration reaches 51ppb, the national winter wheat production will be reduced by 4.132 million tons, which is equivalent to reducing the annual output of Beijing and Shanxi Province. Soybean production decreased by 885,111 tons, which is equivalent to reducing the annual output of Jilin Province. With the increase of ozone concentration, the production reduction will be more serious.

compared with PM2.5, the causes of ozone pollution are more complicated, showing obvious regional distribution and seasonal variation characteristics. At the same time, the detection of some important precursors forming ozone in China is still in its infancy, and there is a lack of corresponding countermeasures, so it is more difficult to prevent and control ozone pollution.

Reference: Shenzhen Government Online-Causes and Main Harms of Ozone Pollution

Reference: People's Daily Online-Ozone has quietly become the primary pollutant in China this summer.