I. What are the ways that air pollutants enter the body? Air pollutants mainly enter the body through the respiratory tract, a small part can also enter the body through the digestive tract and skin. Air pollutants can land to food, water or soil, through diet and water, through the digestive tract into the body, causing harm; also through direct contact with mucous membranes, skin into the body, especially fat-soluble toxic substances are more likely to enter the body through the complete skin. Second, what is the impact of air pollution on human health? The impact of air pollution on health can be divided into acute hazards and chronic hazards: Acute hazards are mainly caused by smoke events or production accidents. When the concentration of air pollutants in a short period of time sharply increased, so that the surrounding population inhaled a large number of pollutants can cause acute hazards, mainly manifested as respiratory and eye irritation symptoms, cough, chest pain, breathing difficulties, sore throat, headache, vomiting, heart dysfunction, lung failure, etc.. Chronic hazards mainly include: (1) long-term irritation, can cause chronic inflammation of the eye and respiratory system, such as conjunctivitis, pharyngitis, bronchitis, etc., serious cause chronic obstructive pulmonary disease (COPD), which can lead to pulmonary heart disease; (2) can cause a decline in the body’s immune function, in areas with serious air pollution, residents salivary lysozyme and secretory IgA content are significantly reduced, other immune indicators are also (3) some pollutants in the atmosphere, such as formaldehyde, the decomposition products of certain petroleum products, certain detergents, etc. have a sensitizing effect, causing the body to have a metamorphosis; (4) atmospheric pollutants often contain benzo(a)pyrene (BaP), arsenic, asbestos and other carcinogens, a large number of investigation data show that air pollution is one of the important causes of lung cancer. In addition, international studies have found that long-term air pollution is also associated with low birth weight, preterm birth, birth defects and other adverse birth outcomes. In addition, air pollution can not only directly affect health, it can also affect our health through long-term indirect effects, such as through the impact of solar radiation and microclimate, the greenhouse effect, damage to the ozone layer, the formation of acid rain, etc. Third, what are the characteristics of air pollution on health effects? (1) air pollution has a wide range of impact, all people living in this environment are exposed, are affected, and can not be prevented; (2) low exposure dose, long duration; (3) is a mixed exposure, the atmosphere contains a variety of pollutants, many of these pollutants often do not exceed the standard, may act alone health hazards are very small, but these substances together in the atmosphere. interaction, the health hazards may be enhanced; (4) although the relative risk of increased health damage to the population of air pollution may not be large, but it is a large population base, so the damage caused is still not negligible. Fourth, which people are susceptible to air pollution? The elderly, children and people with respiratory and cardiovascular diseases are susceptible to air pollution. V. What is the impact of the main pollutants in the atmosphere on human health? The main pollutants in the atmosphere include particulate matter, SO2, NO2 and O3, etc. (1) The health effects of particulate matter: Particulate matter refers to the aerosol state of atmospheric pollutants. The health effects of particulate matter are related to its particle size, composition and concentration. First of all, the particle size of particulate matter determines the possibility of particulate matter entering the human body through the respiratory tract, and the different particle sizes lead to different deposition sites and retention situations in the respiratory tract, which in turn affect the degree of health effects of particulate matter. Particle size greater than 10μm is not easy to enter the respiratory tract; particle size of 5-10μm particles deposited in the upper respiratory tract; particle size of 2.5-5μm particles deposited in the fine bronchi and alveoli; particle size below 2.5μm particles 75% deposited in the alveoli; but less than 0.4μm particles can be more freely in and out of the alveoli and expelled with breathing, so in the respiratory tract of deposition is less. As mentioned above, PM2.5 has a greater impact on health than PM10 from the same source because it is easily retained in the terminal bronchi and alveoli, and some components can penetrate the alveoli and enter the bloodstream. Second, the health effects of particulate matter are closely related to the composition of particulate matter. The organic components of particulate matter can be used as adjuvants to induce asthma or aggravate the symptoms of allergic rhinitis; the polycyclic aromatic hydrocarbon content of particulate matter is related to the carcinogenic activity of particulate matter; particulate matter containing bacteria, viruses, fungi and other microorganisms may cause the epidemic of respiratory infectious diseases; particulate matter adsorbing harmful gases can irritate or corrode the alveolar wall, and the long-term effect can damage the respiratory defense function; the particulate matter on Some metal components also have catalytic effect, can make the atmosphere of certain pollutants into more toxic secondary pollutants. For example, SO2, which is the carrier of particulate matter, can be catalyzed by the metal oxides of the particulate matter into the more corrosive SO3, thus aggravating the damage to the lungs. In addition the composition of some particulate matter is very complex, and the multiple chemical components in particulate matter may also have a combined toxic effect on health. Third, the health effects of particulate matter are also theoretically related to its concentration. However, the health effects of particulate matter lack specific clinical manifestations, the genetic susceptibility of different populations varies, and the pathophysiological mechanisms of particulate matter have yet to be elucidated; in addition, the composition of particulate matter is complex, and the composition of particulate matter from different sources may be very different, so the interaction of particulate matter components on health effects and the risk assessment of particulate matter health effects are still challenging scientific issues. (2) Health effects of SO2: SO2 has an irritating effect on the respiratory mucosa and can cause acute and chronic inflammation of the respiratory tract and reduced lung function; inhalable particulate matter adsorbed with SO2 is considered an allergen and can cause bronchial asthma; SO2 has a certain pro-carcinogenic effect in the process of lung cancer caused by BaP; SO2 is absorbed by the alveoli and can combine with vitamin B1 in the blood and destroy The combination of vitamin B1 and vitamin C in the body under normal conditions, so that the balance of vitamin C in the body is out of balance, thus affecting metabolism and growth and development; in addition, SO2 can also form acid rain and harm health. (3) NO2 on health: NO2 easy to invade the deep respiratory fine bronchi and alveoli, long-term low concentration inhalation can lead to lung tissue damage, causing pulmonary edema, and in serious cases can also cause COPD. epidemiological studies have shown that the increase in bronchitis symptoms in children with asthma is related to long-term exposure to NO2. (4) Health effects of O3: Excess O3 in the air can have an impact on human health. It can cause breathing problems, trigger asthma, reduce lung function and cause lung disease. It is currently one of the air pollutants of greatest concern in Europe. Several European studies report that for every 10µg/m3 increase in exposure to O3, daily mortality increases by 0.3% and heart disease increases by 0.4%. What is the difference in health risk between PM2.5 and PM10? PM2.5 is more harmful to health than PM10: (1) PM2.5 is composed of primary particles emitted directly into the air and secondary particles generated by chemical transformation of gaseous pollutants in the air, and the toxicity of secondary particles is often greater; (2) PM2.5 is more easily inhaled deep into the respiratory tract due to its small particle size, and many harmful substances carried on PM2.5 are then brought to the lungs. The surface area of PM2.5 with the same mass concentration is larger and has a stronger adsorption capacity, and the multiple chemicals attached to it are in closer contact with each other and are more prone to chemical reactions, thus acting as a joint toxic agent or generating more toxic substances, which is more harmful to human health than PM10. Seven, the higher the concentration of PM2.5, the greater the health hazard? The health risk of PM2.5 is related to both its concentration and its components. When the components of PM2.5 are the same, the higher the concentration of PM2.5, the greater the health hazard is; while the components are different, the more toxic and harmful components, the greater the health hazard. In addition, the health hazard of PM2.5 is also related to the tolerance and susceptibility of the population. What are the health effects of hazy weather? The health effects caused by haze weather are mainly acute effects, mainly manifested as upper respiratory tract infections, asthma, conjunctivitis, bronchitis, eye and throat irritation, cough, breathing difficulties, nasal congestion and runny nose, skin rash, cardiovascular system disorders and other disease symptoms enhancement; increased incidence/admission of respiratory system diseases. In addition, haze weather can have some indirect effects on human health. The presence of haze diminishes ultraviolet radiation, and if haze occurs frequently, it affects human vitamin D synthesis, leading to a high incidence of pediatric rickets, and increases the activity of infectious airborne pathogens. Haze weather will also affect people’s mental health, making people depressed, pessimistic and other adverse emotions. Nine, haze weather precautions 1, wear a mask outside the haze weather we should go out as little as possible, cancel the morning exercise, it is best to wear a medical mask protection when you have to go out. When you come back from outside, you should immediately wash your face and bare skin. 2, at home to close the doors and windows in the hazy weather, the home should close the doors and windows, wait until the haze scattered sunrise and then open the windows for ventilation. Air purifier filters can effectively adsorb harmful substances and play the role of air purification. 3, diet light and reasonable haze weather diet should choose easy to digest and vitamin-rich food, eat more fresh fruits and vegetables, which can not only replenish a variety of vitamins, but also play a lung dry, expectorant cough, spleen and kidney role. Eat less stimulating food, eat more pears, oranges, lilies, black fungus, pig’s blood and other foods with the effect of nourishing Yin and moistening the lungs. 4, drink water and do not stay up late Drink water can make the secretory immunoglobulin A and mucus cilia stronger, first of all, drink more water, then pay attention to rest, not to let the body resistance because of staying up late, stress and other factors and decline. 5, dry eyes, drops of “tears” hazy weather easily lead to eye discomfort, such as feeling eye stinging, swelling, foreign body sensation, can go to the pharmacy to buy artificial tears drops into the eyes to relieve discomfort. If the symptoms are more serious, you can use oxyfluoxacin and other eye drops with anti-inflammatory effects. 6, easy to cause cardiovascular disease haze weather is a cardiovascular disease patients “health killer”, especially the elderly with respiratory and cardiovascular disease, foggy days are best not to go out, and should not be morning exercise, otherwise it may induce disease, and even heart attack, causing life-threatening. At the same time, some pathogens in the fog can cause headaches, and even induce hypertension, cerebral hemorrhage and other diseases. Therefore, people suffering from cardiovascular disease, especially the elderly and frail, should not go out on foggy days, and should not be in the foggy day morning exercise, in order to avoid the danger.