In the coldest season of the year, many cities are often shrouded in the shadow of smog. In addition to reporting how the haze weather has seriously affected our lives, most of the news will kindly remind the audience to prevent the occurrence of asthma. What kind of disease is asthma? Why are you so sensitive to air pollution?
What is asthma
Normal people's breathing is soothing and long. If they have shortness of breath, difficulty in breathing, wheezing, shortness of breath, and recurrent attacks, they are asthma. Asthma often breaks out or worsens at night and early in the morning. When asthma occurs, the respiratory muscles contract and spasm strongly, and the inspiratory capacity continues to decline, which will cause serious dyspnea and even life-threatening. Asthma is a common disease. According to the data released by the World Health Organization (who) in 2013, about 235 million people worldwide suffer from asthma. In terms of density, it is equivalent to meeting at least one asthmatic on every fully loaded bus. The most common chronic respiratory disease in children is asthma. In developing countries, the problem of asthma is particularly serious. About 80% of asthma deaths in the world occur in low - and middle-income countries.
Occurrence of asthma
Asthma is often accompanied by allergy. It is a chronic respiratory inflammatory disease involving a variety of immune cells and inflammatory factors. In fact, the respiratory tract of asthmatic patients has been in a slight "inflamed" state. Once they encounter some stimuli, they may induce strong asthmatic symptoms. These stimuli include:
1. Drugs. Drugs with bronchoconstricting effects, such as some cardiovascular drugs, may induce asthma attacks. Aspirin and other drugs can promote the secretion of inflammatory substances and may also aggravate asthma symptoms.
2. Obesity. Recent scientific research has found that obesity may aggravate asthma symptoms. Due to fat accumulation and adipose tissue, it will also cause a certain degree of inflammatory reaction, increase the total amount of inflammatory substances and induce asthma.
3. Allergic substances. Some common allergic substances in life can easily induce asthma, such as dust, hair and mites on bedding, carpets or pets. In outdoor activities, allergic substances such as pollen or mold are also easy to cause asthma.
4. Emotion and exercise. Extreme emotions, such as anger or fear, and physical exercise, can also lead to asthma.
Air pollution and asthma
Knowing the relationship between asthma and inflammatory response, you can probably guess the relationship between asthma and air pollution.
Let's start with the outdoor pollution source PM2 5 and haze. PM2. 5 refers to fine particles with particle size less than 2.5 microns in the air. The main components are sulfuric acid and sulfate, nitric acid and nitrate, and some organic hydrocarbon particles. When they absorb water and grow up, they can form haze. When inhaled, these particles will cause damage to normal lung tissue. This damage will stimulate immune cells, cause immune activation of the body, promote the release of inflammatory factors in the body, and finally induce asthma. At the same time, these particles are also carriers of other pollutants. They can transport some heavy metal elements and organic pollutants directly to the lungs, which can damage lung cells and even cause cancer. At the same time, these particles directly stimulate the bronchus, cause bronchoconstriction and cough, and promote the occurrence of asthma.
Let's talk about indoor air pollution, mainly formaldehyde produced by cigarettes and furniture. Some data show that cigarettes will produce a large number of fine particles during combustion, including formaldehyde, tar, nicotine, carbon monoxide and other harmful substances. These substances can also stimulate the lungs and bronchi and induce asthma. Formaldehyde released by indoor furniture is also an inducement of asthma. If the concentration of formaldehyde is higher than the hygienic standard of 0.1 mg / m3, people will feel uncomfortable; Above 0.6 mg / m3, it will cause discomfort and pain in the throat, and then induce asthma.
Air pollution is one of the reasons that induce asthma, so is there no asthma in a place with clean air? Not necessarily. The incidence rate of asthma in the countries with good air quality is 8% to 18%, much higher than that in the domestic (2% ~ 4%). This shows that there are many factors affecting asthma. A study conducted in Taiwan, China, found that for young girls, indoor smoke volume, precipitation days, carbon monoxide, PM10 index, exercise, smoking, birthplace (city / countryside), allergic symptoms (rhinitis and eczema) and even parental education level were all factors that affect asthma. For boys, age, carbon monoxide, ozone, exercise level, place of birth (urban / rural), parents' education level, alcohol consumption and allergic symptoms were the main influencing factors. It can be seen that asthma is caused by a variety of reasons, and air pollution is only one of them.
Face asthma
Although asthma is a non fatal chronic respiratory disease, it is difficult to cure under the existing medical conditions. Therefore, appropriate life management is the best choice to control asthma. The World Health Organization believes that people with persistent symptoms should take drugs every day for a long time to prevent the emergence and aggravation of symptoms. We also give some suggestions here so that we can understand how to face asthma correctly.
★ patients need to know the common allergic substances around them and avoid contact with these allergic substances. At the same time, follow the doctor's advice and stick to medication.
★ glucocorticoids are essential first-aid drugs for patients with asthma, so they need to be carried with them when traveling.
★ avoid travel in haze weather, or wear masks that can effectively filter fine particles and do necessary protection.
★ absolutely prohibit smoking and avoid inhaling second-hand smoke.
★ when taking medicine in illness, consult the respiratory doctor to avoid asthma induced by the medicine.
★ keep a good mood and avoid getting too excited.
★ with the increase of age, many children diagnosed with asthma in their infancy may have symptom relief. Even so, the respiratory tract of these patients in adulthood is still very sensitive and needs to be paid enough attention.