How is haze formed?

The so-called haze can be said to be a term we are all very familiar with in the past two years. In fact, haze is mainly a kind of fine particulate matter. When the emissions from some social and economic activities reach a certain level, haze is likely to occur.

Among them, sulfur dioxide, nitrogen oxides and inhalable particulate matter are the main components of haze. The first two are gaseous pollutants, and the last one is the main source of air pollution visible to the naked eye. Combined with fog, they affect the visibility range and make the sky gray.

Causes of smog formation

There are many causes of smog, including large-scale emissions of automobile exhaust, exhaust gas generated by burning coal for heating in the north, excessive industrial waste gas emissions, farmers' straw burning, and an increase in toxic substances such as growable particles. Generally, the dry autumn is the peak season for smog. In recent years, large-scale smog with PM2.5 values ​​"off the charts" has occurred frequently, which is also closely related to the worsening environmental pollution.

What is PM2.5

PM2.5 refers to particles in the environment with an aerodynamic equivalent diameter of less than 2.5 microns. The higher its content, the more serious the air pollution. Tiny particles can carry toxic and harmful substances and stay in the atmosphere for a long time, and are transported over long distances, penetrating deep into the respiratory tract and even reaching the bronchi and alveoli, directly affecting the ventilation function of the lungs and making the body susceptible to hypoxia. About 2.1 million people die each year worldwide from rising concentrations of particles such as PM2.5.

The harm of haze environment

Haze weather is most likely to induce cardiovascular diseases and respiratory infections. Due to the low air pressure and high humidity in haze weather, the human body cannot sweat normally, so it has a certain suppressive effect on the cardiovascular system. When harmful particles including heavy metals enter the respiratory tract and stick to the alveoli, it will cause respiratory diseases and even sclerosis and cancer of the lungs.