What is the cause of the smog incident in London?

London is a big city with a history of more than 2,000 years, located in the open valley of the Thames. 1952 65438+From February 5 to 8, in the middle of winter, London was affected by the anticyclone climate, with dense fog and a sudden drop in temperature. The air is still, the fog is still, the city is shrouded in dark clouds, and the whole city of London is submerged in smoke. At the same time, thousands of chimneys in factories and homes still emit a lot of black smoke into the sky. They gather in the sky and cannot spread, which makes the concentration of pollutants in the air increase continuously. The highest concentration of smoke and dust is 4.46 mg 1 m3, which is 0/0 times of normal/kloc-0. The highest concentration of sulfur dioxide reached 65438 0.34%, which was six times that of normal. The streets of London are full of the smell of soot and sulfur. Traffic policemen had to wear gas masks, while pedestrians covered their noses with handkerchiefs to wipe their tears while walking. The tragedy finally happened. A group of award-winning cows will be exhibited at the Expo. They have difficulty breathing and their tongues are leaking. One of them died on the spot, 12 people were dying, and 160 people had convulsions one after another and needed urgent treatment. What followed was that the citizens could not escape bad luck, and several people felt chest tightness, accompanied by cough, sore throat and vomiting. Subsequently, the number of deaths of the elderly, infants and patients increased, and the situation became more serious on the third and fourth days. The morbidity and mortality rate rose sharply, and 4000 people died in four days. According to statistics, people over the age of 45 die the most, about three times as much as usual; The death rate of children under one year old is about twice as high as usual. According to statistics, during 1 week, 704 people died of bronchial inflammation, 9.3 times that of the previous week; 28 1 person died of coronary heart disease, 2.4 times that of the previous week; 244 people died of heart failure, 2.8 times that of the previous week; 77 people died of tuberculosis, 5.5 times that of the previous week; The mortality rate of patients with respiratory diseases such as pneumonia, lung cancer and influenza has also increased exponentially. Even within two months after the incident, 8,000 people died one after another. This is the London smog incident that shocked for a while. Until 12, 10, a brisk westerly wind blew the fresh air in the North Atlantic, dispersed the poisonous fog that pervaded London, and made people see the light of day again and relieved their pain.

London smog cartoon

The smog in London has a long history. 1873, 1880, 189 1 There were three poisonous fog incidents caused by coal burning, and the death toll was about 1800. This situation has happened many times in the future. The authorities turned a blind eye to this and the problem became more and more serious. After the "1952" incident happened again, the British society was in an uproar and asked the government authorities to investigate the victims. However, the reasons were not identified and effective preventive measures were not taken, which led to several smog incidents. For example, in the case of 1962, the climate change is similar to 1952, the concentration of sulfur dioxide in the air is higher than 1952, but the concentration of smoke and dust is only half of 1952, which makes the mortality rate lower than 1952 by 80%. Under the pressure of the people, the British authorities had to conduct in-depth research again, and finally found out that the cause of the London smog incident was that coal contained ferric oxide, which could promote the oxidation of sulfur dioxide in the air, generate sulfuric acid liquid, attach to the smog or condense on the fog core, and enter the human respiratory system, making people sick or accelerating the death of patients with chronic diseases.