Which major cities have ever suffered from smog pollution in history?

The topic of air pollution is nothing new to Parisians, but the period between late November and mid-December last year was one of the worst winter pollution peaks in a decade. From 30 November to 17 December, the Île-de-France region experienced an 18-day peak of pollution, with 11 of those days when pollutant levels exceeded the notification or warning limits (10 days PM10 and 1 day of nitrogen dioxide), while on December 1 PM10 reached a daily average of 146 GHz, almost double the warning limit (80 GHz). The peak of pollution under the influence of the anticyclone did not lead to a significant reduction in visibility as in previous spring peaks, but in the week from November 30 to December 7, the number of patients visiting the paediatric emergency department for respiratory diseases increased by 35% compared to the same period last year, according to the regional health facilities.

1. Maas Valley Smog Incident: In December 1930, one of the main pollutants was soot, 2. Los Angeles Photochemical Smog Incident: In May and October 1943, one of the main pollutants was soot, 3. Donora Smog Event: In October 1948, one of the main pollutants was soot, 4. London Smog Incident: In December 1952, one of the main pollutants was soot, 5. Four Days Event: In December 1952, one of the main pollutants was coal dust and metal dust

Mainly in northern cities, Beijing-Tianjin-Hebei, Shenyang, Changchun, Harbin and other regions. Smog is particulate matter that is less than a micron in diameter, and although it looks like fog, it is solid.

Causes of haze:

Coal straw burning, which is also a reason why the northern winter is prone to haze.

Vehicle exhaust emissions.

Industrial exhaust emissions, the main smog in London that year**.

All kinds of dust in life, dust and water vapor combined to float in the air will form haze.

Hazards of smog:

1.It is harmful to the respiratory system, easy to cause acute rhinitis, bronchitis, and may cause lung cancer in severe cases.

2.It causes cardiovascular and cerebrovascular diseases, leading to cardiovascular disease, hypertension, coronary heart disease, cerebral hemorrhage, may induce angina, myocardial infarction, heart failure, etc., and causes chronic bronchitis to cause cor pulmonale.

3.Affects male fertility.

Prevention and control of smog: The overall management depends on the state, but we must also have a sense of prevention.

1.Exercise time and intensity are appropriately reduced outdoors.

2.When you go out to wear a mask, it is recommended to buy a lot of masks at a time, and cut one after two or three days to see the condition of the filter element, so as to judge the use cycle and effect of each mask.

3.Protect your lungs, eat more foods that nourish your lungs, and drink plenty of water.

4.Indoor air purification: the effect of the air purifier is not very good, it is best to install a set of Haoting household ductless fresh air system in your own house, the PM value of the air outlet can reach 0, and the PM value in the whole room is also between 7-15, the effect is very good.

The conditions and causes of smog include two aspects:

First, the climatic conditions, the air humidity is close to saturation and the atmosphere is stable;

Car exhaust, residential fumes, and burning coal should be the main sources of pollution! Diesel cars and motorcycles should be well managed. Serious smog in big cities is also a disease in big cities, and the excessive concentration of population is not conducive to the diffusion of pollutants!

Fertilizers contribute the most to smog! Ammonia nitrogen.

High-rise buildings are taller than mountains, affecting wind and direction ......As a result, the purification ability of alpine nature is very poor! Automobile exhaust pollution is serious. Serious traffic jams and engine performance development should be strengthened! Diesel locomotives are recommended to install exhaust gas ** equipment!

Why is it easy to form smog days in many cities in China?