What are the hazards of foggy days?

Haze is a combination of fog and haze. Smog is very common in cities. In many areas of China, fog and haze are combined as disastrous weather phenomena for early warning and forecasting, which are collectively called "haze weather".

Haze is the result of interaction between specific climatic conditions and human activities. The economic and social activities of high-density population will inevitably emit a large number of fine particles (PM 2.5). Once the emission exceeds the atmospheric circulation capacity and carrying capacity, the concentration of fine particles will continue to accumulate. At this time, if it is affected by calm weather, it is easy to have a wide range of smog.

The main hazards of smog can be summarized into two types: one is the harm to human body, and the other is the harm to traffic.

1, harm to human body:

(1) on the respiratory system.

The composition of smog is very complex, including hundreds of atmospheric chemical particles. Among them, aerosol particles smaller than 10 micron are harmful to health, such as mineral particles, sea salt, sulfate, nitrate, organic aerosol particles, fuel, automobile exhaust, etc., which can directly enter and adhere to human respiratory tract and alveoli. In particular, submicron particles will be deposited in the upper and lower respiratory tract and alveoli respectively, causing acute rhinitis and acute bronchitis. For patients with chronic respiratory diseases such as bronchial asthma, chronic bronchitis, obstructive emphysema, and chronic obstructive pulmonary disease, smog weather will make the condition acute or acute. Staying in this environment for a long time will also induce lung cancer.

(2) Effects on cardiovascular system.

Hazy days also have a serious impact on cardiovascular and cerebrovascular diseases, which will hinder normal blood circulation, lead to cardiovascular diseases, hypertension, coronary heart disease, cerebral hemorrhage, and may also induce angina pectoris, myocardial infarction and heart failure. And cause pulmonary heart disease in chronic bronchitis.

In addition, when the air pressure is relatively low in foggy weather, people will feel irritable and their blood pressure will naturally rise. On the other hand, in foggy days, the temperature is often low. Some patients with hypertension and coronary heart disease suddenly go from warm indoor to cold outdoor, and blood vessels expand with heat and contract with cold, which will also increase blood pressure, leading to stroke and myocardial infarction. Therefore, patients with cardiovascular and cerebrovascular diseases must take medicine on time and handle it carefully.

(3) Hazy weather will also lead to the weakening of ultraviolet rays in the surface layer, which can enhance the activity of infectious bacteria in the air and increase infectious diseases.

(4) It is not conducive to children's growth. In foggy days, due to the decrease of sunshine, insufficient ultraviolet radiation for children, insufficient production of vitamin D in the body, and greatly reduced absorption of calcium, rickets in infants and young children will be seriously caused, which will slow down the growth and development of children.

(5) Affect mental health.

Experts point out that continuous foggy days have an impact on people's psychology and body. Psychologically speaking, foggy days will give people a feeling of depression, which will stimulate or aggravate the state of psychological depression. In addition, due to the weak light and low air pressure in foggy days, some people will feel lazy and depressed in foggy days.

(6) affecting reproductive capacity.

Studies have shown that the success rate of sperm in vitro fertilization may be reduced in people who have been exposed to high concentrations of polluted air for a long time. The researchers also found a correlation between toxic air and the decline of male fertility.

20 13 1 1.5 The Green Paper on Climate Change: Report on Coping with Climate Change (20 13) jointly issued by China Academy of Social Sciences and China Meteorological Bureau pointed out that in recent 50 years, the smog weather in China has generally shown an increasing trend. Among them, the number of foggy days decreased significantly, the number of haze days increased significantly, and the process of persistent haze increased significantly.

Haze weather will have a significant negative impact on climate, environment, health and economy, such as acid rain and photochemical smog in urban atmosphere, which will reduce atmospheric visibility and hinder air, water and land traffic; Increase mortality, aggravate chronic diseases, aggravate respiratory and heart diseases, change lung function and structure, affect reproductive capacity and change human immune structure.

2. Harm to ecological environment and traffic:

(1) affects traffic safety.

In foggy days, due to poor air quality and low visibility, traffic jams and traffic accidents are easily caused. In daily driving, you should observe the road conditions to avoid danger.

(2) Hazy weather is more likely to cause cancer.

In foggy days, the light is seriously insufficient, the ultraviolet rays near the bottom are obviously weakened, and the bacteria in the air are difficult to kill, thus greatly increasing the probability of infectious diseases. Zhong Nanshan, academician of China Academy of Engineering and director of Guangzhou Institute of Respiratory Diseases, once pointed out at a forum that in the past 30 years, the smoking rate of the public in China has been declining, but the prevalence of lung cancer has increased more than four times. This may be related to the increase in haze days. Not only foggy days with very low visibility will have an impact on human health, but also foggy days and cloudy days will have the same problem.

(3) Affect the ecological environment.

Haze weather has an important impact on roads, railways, aviation, shipping, power supply systems and crop growth. Fog and haze will cause air quality decline, affect the ecological environment and bring great harm to human health.