The haze is coming again! What is haze? How to deal with haze? Does it work to close the window on a foggy day? Which kind of mask should be more reliable
don’t worry, Xi’an health and Family Planning Commission reminds the public: be familiar with the following nine little knowledge about haze, and easily deal with autumn and winter haze with your family
before we know something, we need to look at this picture:
through a simple understanding of air pollution, we can answer some common questions:
1. What is haze” What is the relationship between “fog” and “haze”
“fog” refers to the suspended body composed of a large number of tiny water droplets or ice crystals in the near surface air layer. The appearance of fog reduces the visibility. Generally, the weather phenomenon that the horizontal distance of visibility is less than 1000 meters is called “fog”. According to the degree of fog, there are light fog and heavy fog. According to the horizontal visibility of fog, it can be divided into light fog, heavy fog and dense fog. When the horizontal visibility is between 1000 and 10000 meters, it is called light fog; when the horizontal visibility is less than 1000 meters, it is called heavy fog; when the horizontal visibility is less than 500 meters, it is called heavy fog
“haze” is a kind of weather phenomenon with chaotic atmosphere. Due to a large number of extremely fine aerosol particles (smoke, dust, salt particles, etc.) floating in the air evenly, it is caused by the scattering of sunlight. The atmosphere was opaque, like a thin curtain, with horizontal visibility below 10000 meters. Look at the dark objects in the distance, slightly light blue; When the background is bright (SKY), the thin screen is light yellow, khaki or orange. Haze can be divided into dry haze and wet haze. The relative humidity of the former is generally less than 60%, while that of the latter is more than 70%
haze is just a simple and general statement about weather phenomena. Fog and haze are not the same thing. They are different and related
generally speaking, the difference between fog and haze mainly lies in the size of water content. 1f the moisture content reaches more than 90%, it is called fog, and if the moisture content is less than 80%, it is called haze. 80% ~ 90% is the mixture of fog and haze, but the main component is haze
in terms of visibility, if the horizontal visibility of the target object is reduced to less than 1000m, it is fog; 1f the horizontal visibility is between 1000m and 10000m, it is called light fog or mist; Horizontal visibility less than 10000 meters, and is caused by dust particles, is haze or haze< There are also differences in thickness and color between haze and fog: the thickness of fog is only tens of meters to 200 meters, while that of haze is 1000 meters to 3000 meters; The color of fog is milky white and cyan white, while haze is yellow and orange gray; The boundary of fog is very clear. After passing the "fog area", the sky may be clear, while the boundary between haze and surrounding environment is not obvious there is a connection between them. When the water vapor contained in the air reaches the maximum, saturation occurs. 1f the water vapor is more than the saturation amount, the excess will condense and combine with the tiny dust particles in the air to form small water droplets or ice crystals, which will be suspended in the air layer near the ground and become fog. The lower the temperature is, the less water vapor can be contained in the air, and the easier it is to form haze. Fog itself is not pollution, but the atmospheric environment that produces fog is in a relatively stable state, pollutants are not easy to spread out, resulting in agglomeration effect, which will make the pollution more and more serious. Similarly, under the condition of low pressure and small wind, urban pollutants combined with water vapor in the lower air will aggravate the degree of haze< What is the relationship between "haze" and PM2.5< Many people think that haze and PM2.5 are the same thing. 1n fact, PM2.5 is only one part of haze. The reason why it is easy to be confused is that PM2.5 (fine particulate matter) is the main component of haze, which is the most harmful to human body and the "culprit" of haze. Therefore, the key to control haze is to solve the problem of PM2.5. Therefore, many news or articles will regard PM2.5 as the "pronoun" of haze, causing a kind of error in the public's concept. Compared with the coarse atmospheric particles, PM2.5 has small particle size, large area, strong activity, and easy to carry toxic and harmful substances (such as heavy metals, polycyclic aromatic hydrocarbons, bacteria, etc.), which will contribute to the spread of diseases, and has a long residence time and long transportation distance in the atmosphere, so it has a greater impact on human health and atmospheric environment quality< 3. What is the relationship among air pollution, air pollution and indoor air pollution air pollution, also known as air pollution, according to the definition of international organization for Standardization (1SO), air pollution usually refers to the phenomenon that some substances enter the atmosphere due to human activities or natural processes, present enough concentration and reach enough time, and thus endanger human comfort, health and welfare or the environment indoor air pollution is a situation in which harmful chemical, physical and / or biological factors enter the indoor air and have direct or indirect, short-term or long-term, or potential harmful effects on human physical and mental health in short, the harmful substances of air pollution (air pollution) enter the atmosphere and endanger human health and the environment, while indoor air pollution is pollutants enter the room and endanger human health. 1n addition, the types, sources and hazards of common pollutants in air pollution (air pollution) and indoor air pollution are also different 4. 1s there no pollution in the room when the doors and windows are closed indoor air pollution comes from outdoor atmospheric environment and human activities (indoor smoking, cooking in kitchen, burning of gas stove, use of air conditioner and refrigerator, and other household appliances will aggravate indoor air pollution. Among them, smoking is the most harmful. One cigarette can increase indoor PM2.5 concentration five times in four minutes And the invisible pollution sources in the indoor environment (interior decoration, ornaments, wall paint and furniture, etc., no matter how good the quality is, all contain chemical substances, which will aggravate the indoor air pollution) closing doors and windows can only reduce part of the air pollution. 1f there are many indoor pollution sources, it will still cause harm to health 5. What are the measures to prevent and control air pollution in 2015, the new version of environmental protection law began to be implemented, and the air pollution control industry is mainly for the purpose of controlling industrial waste gas emissions. The main pollution sources are thermal power, steel, cement and a large number of motor vehicles. For the first three types of pollution sources, the industrial waste gas before the target enterprises discharge is treated to remove most of the sulfide, nitrification and dust in the waste gas, so that the final waste gas discharged into the atmosphere can meet the relevant national standards. Automobile exhaust gas treatment mainly depends on upgrading oil products and reducing sulfur content in fuel to achieve the purpose of reducing sulfide emissions in addition, in order to alleviate air pollution, relevant departments in Xi’an city will take measures in heavily polluted weather, such as the shutdown of construction units, the restriction of motor vehicle tail numbers, the shutdown of coal-fired industrial boilers, the suspension of all kindergartens, primary and secondary schools, and the holding of outdoor large-scale activities, etc. 6. What can individuals do to prevent air pollution green travel, try to take public transport. Don’t burn disorderly. Reduce barbecue and other behaviors that are easy to cause air pollution 7 wear a mask when you go out. Wash your face and bare skin immediately when you come back. When wearing a mask, the mask should be replaced after more than 8 hours. Keep the indoor clean and sanitary, reduce the indoor pollution caused by human factors. Haze weather few windows, do not advocate sooner or later window ventilation, it is best to wait for the sun to open the window ventilation. When cooking in the kitchen, use a range hood. 1f you have a light diet and drink more water, you should choose a light, digestible and vitamin rich food, drink more water and eat more fresh vegetables and fruits. 1n this way, you can not only supplement various vitamins and inorganic salts, but also moisten the lung and remove dryness, eliminate phlegm and cough, and strengthen the spleen and kidney. Eat less stimulating food, eat more pear, loquat, orange, orange and other lung clearing phlegm food when children go out, they can wear comfortable protective masks with low respiratory resistance. You can choose a mask with high dust resistance efficiency, which can block the fine particles below micrometers and close to the face, so as to prevent dust or pathogenic microorganisms from entering from the unsealed place. On the diet, you can make some lung clearing meals for your baby, eat less pungent food, eat more tofu, milk and other foods, and supplement vitamins when necessary. Haze serious, many children have a dry cough, throat itching and other symptoms. 1n the face of haze weather, in addition to trying to let children go out less, try to be indoor activities pregnant women should rest properly, reduce going out, wear masks when going out, avoid overwork, ensure adequate sleep and reduce psychological pressure. Eat more zinc food; Supplement vitamin, improve indoor air relative humidity patients with cardiovascular system, respiratory diseases and eye diseases, especially patients with dyspnea and the elderly, should avoid going out or taking part in outdoor activities in the morning when the fog is thick or rush hour, reduce the time of going out, wash face frequently after going out, drink more water, and pay attention to rest. 1f you feel unwell, go to the hospital< What are the health hazards of air pollution the impact of air pollution on health can be divided into acute and chronic hazards the acute harm is mainly caused by the rapid increase of the concentration of air pollutants (especially outdoor ambient air) in a short time (such as severe haze), and the acute harm caused by a large number of people inhaling pollutants, mainly manifested as respiratory and eye irritation symptoms, cough, chest pain, dyspnea, sore throat, headache, vomiting, cardiac dysfunction, pulmonary failure, 1nduced acute attack of chronic cardiovascular and cerebrovascular diseases chronic hazards mainly include: (1) chronic inflammation of the eye and respiratory system caused by long-term stimulation, such as conjunctivitis, laryngitis, tracheitis, etc., which can seriously cause chronic obstructive pulmonary disease (COPD), and then lead to pulmonary heart disease( 2) The contents of lysozyme and secretory 1gA in saliva of residents in areas with serious air pollution were significantly decreased, and other immune indexes were also decreased( 3) Aggravating chronic cardiovascular and cerebrovascular diseases( 4) 1t can aggravate allergic reaction or allergic disease. 1f some pollutants in the atmosphere have sensitization effect, it can aggravate asthma, allergic rhinitis and other diseases( 5) The 1nternational 1nstitute of cancer (1ARC) has classified air pollutants, including particulate matter, as a class a carcinogen. The review articles published in the world believe that although the overall risk of air pollution for cancer is relatively low, but for lung cancer, air pollutants, especially particulate matter, often contain benzo (a) pyrene (BAP), benzo (a) pyrene (BAP) and Arsenic and other carcinogens have high risk. 1n addition, international studies also found that long-term air pollution is also associated with low birth weight, premature birth, birth defects and other adverse birth outcomes< 1n addition, air pollution can not only directly affect health, but also through long-term indirect effects, such as solar radiation and micro radiation