Ozone air pollution has become the culprit than PM2 5 management is more

Photo: network

Released on September 16, according to the Department of environmental protection, August national air quality exceeds the number of days in 74 cities in key areas, most of days with ozone as the primary pollutant, followed by the familiar PM2. 5. This is since May, ozone PM2 for a fourth consecutive month. 5, becoming the air quality standard of "culprits".

High concentrations of ozone near the ground can irritate and damage the eyes, respiratory system and other mucosal tissues, have a negative effect on human health. Experts say that from long observation, while ozone standard been ample sunshine from April to September, but foreign experience as national PM2. 5 increased governance, improve visibility in air, ozone exceeded the increased probability of occurrence, and ozone pollution than PM2. 5 the governing more difficult.

Ozone exceeded for 3 consecutive years drag on the air quality in August

Since the summer of this year, Beijing's blue sky significantly more than in previous years, but in mid-August, the Ministry of environmental protection announced in July the country's 74 urban air quality shows, Beijing's air quality rankings drop, not rise, ranked tenth. From May to August, monitoring Beijing's air quality "standard day", and ozone are the primary pollutants of up, followed by PM2. 5.

In 2013, the national implementation of new ambient air quality standards since the ozone air quality in many cities exceeded the primary pollutant. According to data published by the Department of environmental protection in August 2013, 74 cities in air quality exceed the number of days, days with ozone as the primary pollutants accounted for more than 70%, PM2. 5 accounting for only 19. 8%. In August 2014, 74 cities main pollutant is ozone. In August, the pattern continued for two years, ozone becomes "dragged down" air quality "culprits".

"Many recent studies have shown that ozone is becoming in addition to PM particles, and pollutants of greatest impact on ambient air quality. "The Department of environmental protection environmental planning Institute of atmospheric environment leiyu, Deputy Director of the Department said.

According to leiyu introduced, ozone standard is currently concentrated in Beijing, Tianjin and Hebei, Yangtze River Delta, Pearl River Delta and Shandong, Henan and other places, and showed an increasing trend. Current ozone pollution also is a regional issue, not a national problem.

Institute of atmospheric physics, Chinese Academy of Sciences researcher Wang Yue thinking that the current, nationwide, northern peak ozone exceeded 1 every year, while the South has 2 peaks a year, even some western regions also face excessive ozone problems.

Although different in scope, but experts generally agreed that the ozone standard has become a must in the face of a new subject of environmental protection. "Come a long way in order to avoid ozone pollution treatment, the current, from the source has become essential. "Wang Yuesi said.

Ozone pollution causes acute danger high temperature light turned into a Guo mother in the courtroom, declined to be interviewed:

"The day was Buddha, is magic" is a recognized description of ozone research. Gathered in the stratosphere, ozone is "champions of the Earth" to absorb the Sun's ultraviolet light; near the ground, high concentrations of ozone can irritate and damage the eyes, respiratory system and other mucosal tissues, have a negative effect on human health.

"The toxicity of ozone mainly reflected on its strong oxidizing, and can break down the cell walls, causing the danger are acute. Harm to the human body are mainly affects the respiratory system, easy on the lungs cause acute harm, such as emphysema. In recent years a growing number of asthma, and some may be related to ozone pollution. "School of public health, said Pan Xiaochuan, a professor at Peking University.

Zhang Xinmin, a researcher at the China Environmental Science Research Institute said current studies have shown that ozone pollution to human body, especially the eyes, respiratory tract, lungs, and other effects. In addition, the high ground-level ozone can cause crop or dead trees.

Representation of the ozone is a photochemical smog pollutants. History of the famous United States Los Angeles smog event is the typical case of ozone pollution. In 1955, in the event of a severe smog pollution in Los Angeles, ozone concentrations as high as over 1300 μ g per cubic metre, seriously affecting people's health.

Due to the ozone damage growing, increasingly stringent international safety standards for ozone, China's newly revised the standards for ambient air quality has also increased controls on ozone standards. According to current national standards, ozone hourly concentrations exceed 200 µg/m, which reached "level 3 light pollution" levels as "excessive".

Why ozone is exceeded? Director of the Beijing environmental protection monitoring Center said Zhang Dawei, ground-level ozone, in addition to a small amount from stratospheric transport outside, mostly due to man-made emissions, "nitrogen oxides" and "volatile organic compounds" (VOCs), secondary transformation at high temperature under light conditions. "Nitrogen oxides come from motor vehicles, power plants, coal-fired boilers and cement kiln emissions; volatile organic compounds come mainly from motor vehicles, petrochemical industry emissions and volatile organic solvents, and so on. "

Deputy Huang Yuhu, Director of the Institute of environmental sciences of Beijing air pollution prevention and control introduction of volatile organic compounds on PM2. 5 the two pollutants and ozone formation plays a key role. "First of all, volatile organic compounds can react with free radicals in the atmosphere to form secondary organic aerosols, the PM2. One of the 5 main components. Secondly, volatile organic compounds and nitrogen oxides in UV-irradiation conditions, a series of photochemical reaction, improved atmospheric corrosion, may lead to higher concentrations of ground-level ozone, accelerating the generation of secondary fine particles. That's why summer ozone more easily exceeded. "

Ozone pollution than PM2. 5 governance more difficult

Many experts said that with the PM2. 5 increased governance, improve visibility in air, ozone pollution problems will become more prominent. From international experience, ozone pollution than PM2. 5 the governing more difficult.

Concentrations of ozone and its precursors nitrogen oxides and volatile organic compounds in complex relationships between, scientific research shows that not reduce nitrogen oxides and volatile organic compounds, ozone concentration is reduced, when you control the ratio between them is not suitable for, ozone concentrations in the air may also be increased within a short time. Therefore, control of ozone concentration is not a simple emission reductions of nitrogen oxides and volatile organic compounds.

"Ozone pollution control is still at an early stage in our country, how to develop emission reduction of volatile organic compounds and nitrogen oxides, effectively reducing ozone concentrations, one of the difficulties is the current treatment of ozone pollution. "Atmospheric pollution prevention Division, Department of Environmental Protection Department official told reporters.

According to experts, volatile organic compound species thousands of sources is very complex, covering petrochemical, chemical industry, automobile manufacturing, printing, furniture production or use, such as paint, paint and solvent in industrial enterprises, control techniques varied, different advantages and disadvantages of each technology, which also pose great challenges for controlling ozone.

Said Zhang Yuanhang, ozone pollution prevention is the key to continuous improvement of air quality, ozone cannot be effectively controlled if PM2. 5 governance will be wasted effort, or to some extent exacerbated the PM2. 5 pollution. "The urgent need to establish ozone national ambient air quality management and the PM2. 5 as the core of multi-pollutant control strategies, to develop national, regional and city levels of ozone pollution control measures. "

Emission source for many kinds of volatile organic compounds, complex situation, leiyu proposals in petrochemicals, organic chemicals, coating, packaging and printing industries, implemented comprehensive treatment of volatile organic compounds. In addition, a large number of gas stations, dry cleaners, printing and other "little sources" the control can not be ignored, reducing vehicle exhaust emissions are one of the necessary tools.

Experts have warned, after several years of PM2. 5 popularization of knowledge, people see air know PM2. 5 index exceeded the serious air pollution. In front of blue sky and white clouds, few people realize the danger of excessive ozone should disseminate knowledge about ozone pollution and allow more people to pay attention to this invisible invisible pollution.