All information about pm2.5

PM is called particulate matter in English. Scientists use PM2.5 to represent the content of this particle in every cubic meter of air. The higher this value, the more serious the air pollution.

Inhalable particulate matter and total suspended particulate matter in daily or weekly reports of urban air quality are two common air pollutants.

Inhalable particulate matter, also known as PM 10, refers to particulate matter with a diameter greater than 2.5 microns and equal to or less than 10 microns, which can enter the human respiratory system; The total suspended particulate matter is also called PM 100, that is, particles with a diameter less than or equal to 100 micron.

The main source of PM2.5 is the residue discharged from combustion during daily power generation, industrial production and automobile exhaust emission, most of which contain toxic substances such as heavy metals.

Generally speaking, coarse particles with a particle size of 2.5 microns to 10 microns mainly come from road dust; Fine particulate matter (PM2.5) below 2.5 microns mainly comes from the combustion of fossil fuels (such as automobile exhaust and coal burning) and volatile organic compounds.

Meteorologists and medical experts believe that smog weather caused by fine particles is even more harmful to human health than sandstorms. Particles with a particle size larger than 10 micron will be blocked outside the human nose; Particles with a particle size of 2.5 microns to 10 microns can enter the upper respiratory tract, but some of them can be excreted through sputum and blocked by villi inside the nasal cavity, which is relatively harmless to human health; However, fine particles with a particle size below 2.5 microns have a diameter equivalent to that of human hair110, and are not easy to be stopped. Inhalation into the human body will directly enter the bronchus, interfere with the gas exchange in the lungs, and cause diseases including asthma, bronchitis and cardiovascular diseases.

Each person inhales about 654.38+00000 liters of air every day, and the dust entering the alveoli can be absorbed quickly, directly entering the blood circulation and distributed throughout the body, without detoxification of the liver. Secondly, it will damage the ability of hemoglobin to transport oxygen and make blood lose. It may have serious consequences for patients with anemia and blood circulation disorders. For example, it will aggravate respiratory diseases and even cause heart diseases such as congestive heart failure and coronary artery. In short, these particles can also enter the blood through bronchi and alveoli, and harmful gases and heavy metals are dissolved in the blood, which is more harmful to human health. The physiological structure of human body determines that it has no ability to filter and block PM2.5, but the harm of PM2.5 to human health has gradually exposed its horrible side with the progress of medical technology.

In EU countries, PM2.5 has reduced people's average life expectancy by 8.6 months. PM2.5 can also be a carrier of viruses and bacteria, which is helpful for the spread of respiratory infectious diseases. At present, the major developed countries in the world and Japan, Thailand and India in Asia have listed PM2.5 in the air quality standard. The most tragic thing is that PM2.5 has not been included in China's ambient air quality index, so it has become the root cause of the direct conflict between the data of the US Embassy and the official government data.

The World Health Organization also pointed out in the 2005 edition of the Air Quality Guide that when the average annual concentration of PM2.5 reaches 35 μ g/m3, compared with the situation of 10 μ g/m3, the risk of human death will increase by about 15%. According to the report of the United Nations Environment Programme, if the concentration of PM2.5 per cubic meter increases by 20 mg, about 340,000 people will die in China and India every year.

In this section, the standard of editing monitoring standard PM2.5 was put forward by the United States in 1997, mainly to monitor the fine particles that appeared with the increasingly developed industrialization and were ignored in the old standard and were harmful to human health. The PM2.5 index has become an important indicator to measure and control the degree of air pollution.

By the end of 20 10, except that some countries in the United States and the European Union have included PM2.5 in the national standard and imposed mandatory restrictions, most countries in the world have not carried out monitoring of PM2.5, and most countries generally monitor PM 10.

The World Health Organization (WHO) believes that PM2.5 less than 10 is a safe value, while all these areas in China are above 50, close to 80, far higher than the Sahara desert. [1] Monitoring comparison 2011/February 5, foggy weather occurred in northern China, with visibility less than one kilometer, which led to the closure of highways between several provinces and the delay or cancellation of more than 300 flights to Beijing.

Citizens traveling in foggy weather

The us embassy in China publishes the monitoring data of PM2.5 every hour. The data shows that at 20119 on the evening of February 4, the US Embassy in China monitored that the PM2.5 concentration in Beijing was 522, the air quality index (AQI) was 500, and the health warning was "beyond the index".

201165438+February 5, the deadline for public comments on the Environmental Air Quality Standard (the second draft for comments). The opinion draft proposes to increase the average daily concentration limit of PM2.5 and the 8-hour ozone concentration limit in the basic monitoring project, and the new standard is planned to be fully implemented in 20 16.

In the standard exposure draft, the annual and 24-hour average concentration limits of PM2.5 are set at 0.035 mg/m3 and 0.075 mg/m3, respectively, which are the same as the target values of the World Health Organization (WHO) in the transition period 1 stage. According to the person in charge of the Science and Technology Standards Department of the Ministry of Environmental Protection, there are three major breakthroughs in the ambient air quality standard (draft for comment): First, adjust the division plan of ambient air quality functional zones and merge the three types of zones in the current standard into the second type; The second is to improve pollutant projects and monitoring standards, including increasing the average annual and daily concentration limit of PM2.5 and the 8-hour concentration limit of ozone in basic monitoring projects, and tightening the concentration limit of PM 10 and NO2. The third is to improve the validity requirements of data statistics. This is the first time that China has formulated national environmental quality standards for PM2.5.

Experts say that PM2.5 is a pollutant that seriously harms human health and has been scientifically confirmed. In recent years, the problem of PM2.5 pollution in China has become increasingly prominent. Incorporating PM2.5 into the scope of mandatory pollutant monitoring is conducive to eliminating or alleviating the phenomenon that the public's self-perception is not completely consistent with the monitoring and evaluation results. The annual and 24-hour average concentration limits of PM2.5 are set at 0.035 mg/m3 and 0.075 mg/m3, respectively, which are the same as the WHO target value in the transition period 1 stage, and meet the needs of China's current economic development stage and environmental management.

In addition, Beijing-Tianjin-Hebei, Yangtze River Delta, Pearl River Delta and nine major urban agglomerations may be forced to monitor and publish the data of PM2.5 first, and the Twelfth Five-Year Plan for joint prevention and control of air pollution may be approved by the State Council early next year. At the same time, Wu Dui, a researcher at Guangzhou Tropical Marine Meteorology Institute of China Meteorological Bureau, pointed out that the resistance to the release of PM2.5 came from local areas, and the manufacturing pressure in local areas prevented the release of PM2.5, which is a direct manifestation of the current concept of performance appraisal and the dominance of GDP.

The nine major urban agglomerations are the central Liaoning urban agglomeration, Shandong Peninsula, Wuhan and its surrounding areas, Changsha-Zhuzhou-Xiangtan, Chengdu-Chongqing, the west side of the Straits, Guanzhong, Shaanxi, north-central Shanxi and Urumqi urban agglomerations. [2]

Implementation time

201165438+February 2 1 day, at the seventh national environmental protection work conference, Minister Zhou Shengxian of the Ministry of Environmental Protection announced the schedule of PM2.5 and ozone monitoring, and the nationwide PM2.5 monitoring will be divided into "four steps". He said that in 20 12, PM2.5 and ozone monitoring will be carried out in key areas such as Beijing-Tianjin-Hebei, Yangtze River Delta and Pearl River Delta, as well as municipalities and provincial capitals; Monitoring in 1 13 key environmental protection cities and environmental protection model cities 20 13; 20 15 to carry out monitoring in all cities above the prefecture level, and the deadline for the new standard is 20 16. By then, all parts of the country will monitor and evaluate the ambient air quality according to this standard, and release the monitoring results to the society. [3] Domestic situation According to the AQTI evaluation report issued by Law School of Renmin University of China and Center for Public Environmental Research (IPE) 2011,fine particulate matter monitoring was generally not carried out in 20 domestic evaluation cities such as Beijing, Shanghai, Guangzhou and Chongqing. It is worth noting that the pollution levels in international cities such as London, Paris and new york, which regularly monitor and release PM2.5, are relatively low. At the same time, many large cities in developing countries, such as Mexico City and New Delhi, have already carried out frequent monitoring and release of PM2.5.

From 20 1 1, 1 and 1, the Gravimetric Measurement of Ambient Air PM 10 and PM2.5 (hereinafter referred to as "Measurement") issued by the Ministry of Environmental Protection began to be implemented. This measurement standardized the measurement of PM2.5 for the first time, but in the Environmental Air Quality Standard recently revised by the Ministry of Environmental Protection, PM2.5 was not included in the mandatory monitoring index. [4]

2011110 Zhang Lijun, vice minister of environmental protection of China, said at the 7th international symposium on regional air quality management that the atmospheric environmental quality standard of China PM2.5 will be released soon. The standard will use the value of the first transition period stipulated by the World Health Organization (WHO) to illustrate the pollution hazard of PM2.5 index.

In addition to dust and pm2.5 prevention, the mask fabric also uses Conlon fiber, which can kill "super bacteria" that can't even kill antibiotics. When people keep breathing, pm2.5 particles mixed with a large number of pathogenic bacteria are inhaled by people, which directly infringes on human health. Using masks is undoubtedly an effective solution to the problem of dust prevention and disease prevention.

Try to reduce smoking or even not to smoke. There is a large amount of pm2.5 in smoke, which will cause direct and indirect harm to human body. If you can't stop people around you from smoking, you should try to stay away from the smoke.

You can't do morning exercises in foggy days. PM2.5 is one of the important culprits of foggy weather, so when you get up in the morning and find the fog is heavy, don't go out for morning exercise. If you must do morning exercises, jogging and trotting suggest bringing a mask that can really prevent pm2.5.

Air pollution and climate change need to be dealt with in a unified way, not separately. Because air pollution and climate change are largely caused by emissions from fossil fuel combustion, actions to reduce and control air pollution and reduce greenhouse gas emissions to protect the climate should be consistent. Some studies have pointed out that the increase of atmospheric aerosols reduces the amount of solar radiation reaching the ground, which is contrary to the warming effect of greenhouse gases and offsets each other. 50% of the surface warming caused by greenhouse gases may be offset by the cooling effect of aerosols. Once the aerosol is removed, the warming caused by greenhouse gases will be more obvious, which will further increase the pressure of CO2 emission reduction. Therefore, air quality and climate change cannot be solved in isolation, they are closely related.

It is necessary to develop more complex earth system models and long-term monitoring systems for climate and biogeochemical variables. Using this complex model of the earth system

This strategy is particularly important for China, a developing country with rapid economic development, because these two problems not only exist at the same time, but also contribute to serious air pollution and rapid increase of greenhouse gas emissions due to the rapid growth of economic growth and energy consumption. Solving these two problems from the same source is not only more effective economically, but also can solve the problems of atmospheric environment and climate change at the same time.

In the adjustment of energy structure and industrial structure, the comprehensive or integrated technology of greenhouse gas and aerosol emissions should be considered at the same time, so that both emissions can be reduced and controlled; Organize all forces to compile the first relatively complete aerosol emission inventory in China; Further improve the observation network of greenhouse gases and aerosols, especially the aerosol observation network needs to be expanded and encrypted; Study the aerosol-cloud-climate change interaction between air pollution and climate change, and develop an ensemble model system in which climate models (global and regional models) and air pollution models are coupled and nested, so as to provide scientific basis and support for the establishment of medium and long-term air pollution and its environmental climate impact in China; Establish a coupling risk assessment system of air pollution and climate change, and provide an assessment of the consequences and severity of the impact on social and economic sectors according to their interaction and future scenario prediction. [9]

The smaller the dust, the more difficult it is to filter. According to the EPA laboratory research of the US Environmental Protection Agency, there are three main dust removal methods for air purification (dust removal):

1) Brownian diffusion)-The smaller the particle, the stronger the effect.

2) Screen capture)-The bigger the particles, the better the effect. [6]

The Ministry of Environmental Protection stopped World Environment Day on June 5th, 2065438+02. Wu Xiaoqing, Vice Minister of Environmental Protection, held a press conference in the State Council Press Office, saying that the monitoring and data release of PM2.5 in China by foreign embassies and consulates in China did not meet the requirements of international practice, and China was not rigorous and standardized. It is hoped that individual consulates in China will respect the relevant laws and regulations of China and stop publishing unrepresentative air quality information.

Wu Xiaoqing said that legally speaking, China's Environmental Protection Law, Air Pollution Prevention Law and other relevant laws stipulate that the competent administrative department of environmental protection in the State Council should establish a monitoring system, formulate monitoring norms, organize a monitoring network with relevant departments, and strengthen the management of environmental monitoring; The competent administrative departments of environmental protection of the State Council and the people's governments of provinces, autonomous regions and municipalities directly under the Central Government shall regularly publish bulletins on environmental conditions.

"According to the Vienna Convention on Diplomatic Relations and the Vienna Convention on Consular Relations, diplomats are obliged to respect the laws and regulations of the receiving country and cannot interfere in the internal affairs of the receiving country." Wu Xiaoqing said that the monitoring and release of air quality in China involves public interests and belongs to the public power of the government. The consulates of individual countries in China carry out air quality monitoring on their own and publish air quality information on the Internet, which is not in line with the spirit of the Vienna Convention on Diplomatic Relations and the Vienna Convention on Consular Relations, and also violates the relevant provisions of environmental protection.

The standards of PM2.5 in developed countries around the world, including the United States, are gradually improving. For example, when the United States released the pm 2.5ⅱⅱ II II standard in 1997, it was set at 65 μ g/m3. 10 years later, when this standard was revised in 2006, it only reached 35 μ g/m3. Therefore, the revision of environmental quality standards should be closely related to the level of economic development and technical conditions. The new air quality standards issued by China, in which the daily average value of PM2.5 is 75 μ g/m3, are determined according to China's development level and technical conditions.

Wu Xiaoqing also said that from the release of environmental quality monitoring information, environmental protection departments should further increase the release of monitoring information. "We are fully prepared to release and disclose environmental quality monitoring information in a timely manner. Starting from the second half of this year, 74 cities and all state-controlled monitoring points will release air quality monitoring information one after another to let the public know the monitoring information in time. And the monitoring information and data released by us will be more complete and comprehensive. The real-time concentration values of six pollutant indicators, such as sulfur dioxide, nitrogen dioxide, ozone, PM 10, PM2.5 and carbon monoxide * * *, will be released at one time and matched with the air quality AQI index to make the monitoring items more comprehensive and the monitoring points more representative. "

According to the requirements of the new standard, China's air quality monitoring data is more accurate and standardized, which can fully meet the needs of the public, institutions and personnel for environmental quality information in China. Therefore, it is hoped that individual consulates in China will respect the relevant laws and regulations of China and stop releasing unrepresentative air quality information.