Ozone pollution strong attack? Environmental experts: no serious ozone pollution, but no ozone explosion
just past the summer left to Beijing and Tianjin is the memory of the blue sky More, but often sky transparent, sunny moments, the air quality index in the ozone index will quietly climb. This invisible pollution will quietly pull down the air quality, stimulate the human respiratory mucosa. Near-surface ozone is one of the culprits of photochemical smogs. Photochemical smog events in Los Angeles in the 1950s were one of the eight major public events in the history of mankind, and it was this event that kept scholars wary of the ozone problem.
After PM2.5 into the public eye of ozone, will it become a photochemical event worries? Recently, the China Youth Daily reporter in the Green Online interview with the relevant person in charge of environmental protection and experts.
Researchers have confirmed that near-ground high concentrations of ozone can irritate and damage the eyes, the respiratory system, and so on. And other mucosal tissue, a negative effect on human health. Every 100 tons of ozone per cubic meter of ozone in the air, the human respiratory function will be reduced by 3%. Because of its invisible features, also known as the air “invisible killer”.
Chinese Academy of Engineering, Tsinghua University Professor He Kibin said that the current impact of China’s air quality of the two major pollution factors, one is PM2.5 as the representative of the fine particles, the other is ozone. Environmental protection departments have long been aware of the impact of ozone on air quality, so in 2012 revised air quality standards, ozone has been included in the scope of monitoring, and as an important component of the assessment of air quality.
It is also with the monitoring data changes, which makes the problem of ozone into the public eye.
Chinese Academy of Environmental Sciences researcher Chai Fahe said that China’s current standard of ozone daily maximum 8 hours average concentration of 160 micrograms / cubic meter, close to the United States and other developed countries standards, far more than the World Health Organization The phase transition value of the PM2.5 standard is strict. According to the monitoring data of 2016, there are 59 cities in 338 cities with ozone monitoring data, which are mainly distributed in Beijing, Tianjin and the surrounding areas. Triangular area, southern Liaoning, Wuhan city group, Chengdu and Chongqing region, Shaanxi Guanzhong area. According to the daily evaluation, 338 urban ozone mild, moderate and severe pollution days were 4.7%, 0.4%, 0.024%, no serious pollution, but no ozone “burst table.”
Air Pollution Control Ministry of Environmental Protection Secretary Liu Bingjiang said that the current focus on regional ozone pollution levels in China and the California South Coast region roughly the national average pollution level roughly equivalent to the US national average a decade ago , Are far below the historical level of the frequent occurrence of photochemical smog events in developed countries.
Liu Bingjiang further explained that research shows that developed countries focus on 50 to 70 years of the last century in the Summer and autumn the highest concentration of ozone daily more than 600 micrograms / cubic meter. Occurrence of photochemical smog events, the ozone concentration of up to 1200 micrograms / cubic meter, the highest value even more than 2000 micrograms / cubic meter. From the numerical point of view, China may be the concentration of ozone fluctuations, but under normal weather conditions, and now will not happen photochemical smoke events, the possibility of future occurrence is also very small.
The source of ozone near the ground has been clear in the context of the researchers. It is generally believed that the burning of fossil fuels and industrial enterprises to the air emissions of nitrogen oxides, hydrocarbons, carbon monoxide and volatile organic matter and other pollutants in the role of sunlight under the photochemical reaction of ozone and other secondary pollutants. From the time point of view, the sun strong summer afternoon afternoon, the higher the temperature, relatively low humidity, the more prone to excessive ozone. In short, the formation of ozone precursor is nitrogen oxides and volatile organic compounds, to control the ozone concentration from the control of nitrogen oxides and volatile organic matter to start. China from the “second Five-Year” plan began, has the nitrogen oxides as a binding indicator of emission reduction. “Twelve Five” period, China’s nitrogen oxide emissions fell by nearly 20%. “Thirteen five” plan and further proposed volatile organic matter to reduce emissions of 10% of the target.
Liu Bingjiang said, the trend in recent years for higher emissions of volatile organic compounds, the ministry specifically formulated the “Thirteen Five” volatile organic compounds pollution prevention and control work program, a clear key industries and key areas of control tasks The In fact, Beijing and other places in the “three five” during the volatile organic compounds to take control measures have been effective in 2015, 2016 atmospheric volatile organic compounds in 2014 decreased by 7%, respectively, 9 %.
But Liu Bingjiang also reminded, by theEconomic rebound and meteorological conditions and other factors, this year, many areas of China’s ozone concentration has increased, although the number of days is still slightly polluted mainly due to normal fluctuations in the year, but the nitrogen oxides, volatile organic control and Emission reduction can not be taken lightly.
outdoors under the hot sun is not able to fight against ozone damage
In the expert’s view, slightly exceeded the ozone do not panic. And cleaners, masks against fine particles of different pollution, to prevent ozone pollution is very simple, the sun can hide in the room. According to research, it has been shown that even if the outdoor ozone concentration of about 400 micrograms / cubic meter, the indoor concentration is only tens of micrograms / cubic meter, as long as the summer is not in the hot sun outdoor activities, can be effective Avoid possible health damage from ozone.
scholars believe that the ozone “good ozone” and “bad ozone”, in ambient air near the ground ozone on human health and the environment harmful, “bad ozone”; altitude in the stratosphere Ozone protects surface creatures from strong ultraviolet radiation damage, which is “good ozone”. In addition, people use ozone has a strong oxidizing properties, its use in food and drinking water disinfection, clean indoor air, bath health care. The harm of ozone depends on the combination of three factors: the chemical nature of ozone, the concentration of ozone in the ambient air, the exposure time of the human body or the creature in a certain concentration of ozone, Control exposure time and so on to reduce the damage. Liu Bingjiang said that for the ozone pollution, the public can not only passively respond to health protection, and can take the initiative to participate in the prevention and control work. At present, China’s atmospheric nitrogen oxides concentration showed a downward trend, but the volatile organic matter emissions are still increasing.
“wide range of sources of volatile organic compounds, scattered, difficult to control.” Liu Bingjiang further explained that the decoration of everyday life, painting, travel and other activities are likely to emissions of volatile organic compounds, if the public have preferred to reduce volatile Organic matter emissions of products or services, such as home paint to buy water-based paint, to the home when the oil refueling oil and gas recovery facilities to choose normal, no gasoline flavor of the gas station, then the momentum of volatile organic matter is expected to be reversed, for the ozone pollution control Provide strong support. Reporter Liu Shixin