A huge disaster caused by human destruction

The London Smog Incident is one of the world's most famous public hazard events. It occurred in London, England, from December 5 to 8, 1952.

December 3, 1952, was a lovely winter day in London, England. The Meteorological Observatory reported that a cold front had passed through overnight and by noon, the temperature reached 5.6°C with a relative humidity of approximately 70%. The wind blows comfortably from the north. The sky was dotted with downy cumulus clouds, England's famous clouds that only appear during clear moments. All in all, it was a great day. The elderly and sick were particularly happy. They sat in the sun and drank tea in the clean wind blowing from the North Sea. The wind blew across England, blowing smoke from the chimneys of factories and urban households in the Midlands. London is on the southeastern edge of a huge anticyclone, an area of ??high pressure. Winds blow clockwise around this high-pressure center.

On December 4, this anticyclone moved to the southeast along its usual path, with its center a few hundred kilometers west of London. The wind direction had changed slightly, blowing from the north-northwest direction, and the wind speed was higher than the original Slow. Several layers of clouds almost obscured the sky. Through the cracks in the broad and uniform dark gray stratus clouds in the lower layers, we could see higher clouds at an altitude of about 3,000 meters. They cover the sun and the sky. The temperature at noon was 38°C and the relative humidity was 82%.

The air is filled with the smell of smoke. Soot and ash particles from thousands of chimneys drift quietly into the atmosphere. Large particles fall on roofs, streets, and on hats and clothing. Smaller pieces of smoke drifted in the air. As playing children ran in and out of the house, gusts of wind brought the smoke and gas indoors. Smoke even finds its way into a house with closed doors and windows; when the indoor and outdoor temperatures change, the house "inhales" the polluted outside air and "exhales" the cleaner indoor air. However, considering all factors, the weather on December 4th was not too bad, it just seemed bad compared to the previous day. In the following days, people in London realized how terrible the weather was.

On December 5, the high pressure center had almost moved over London. The wind was very weak and the fog reduced visibility to the point where walking was difficult. The temperature at noon was 33°C and the relative humidity was about 80%.

The smell of smoke gradually became stronger. The wind is too weak to blow away the smoke from the chimney. Smoke and moisture accumulate in the atmosphere thousands of meters above the ground. People began to complain to each other about their neighbors, and car drivers muttered curses about the fog.

On December 6, the situation got worse. Thick fog covered the entire sky, and the city was at the western end of the anticyclone. The temperature dropped to -2°C at noon, while the relative humidity rose to 100%, and atmospheric visibility was only a few dozen feet. All plane flights were cancelled, and only the most experienced drivers dared to take to the roads. People on foot groped along the sidewalk. The anemometer does not rotate and reads zero. Because the air flow is too slow to rotate the cup on the anemometer, the wind speed does not exceed 23 kilometers per hour. The breeze, sometimes barely perceptible, blows now one way, now the other. As the air hangs stagnantly over cities, factory boilers, home fireplaces and other smoking furnaces add toxins to the air. The mist droplets are mixed with some gases and particles in the smoke. The mist is no longer clean mist, nor is it clean water droplets anymore, but a mixture of smoke and mist, which we call "smoke".

Smoke filled the city, attacking everything that was alive. When people's eyes feel it, tears will flow down their cheeks. Every time you take a breath, you inhale a lung cavity of polluted gas. Coughing can be heard wherever there are people. People lecturing in the school had to raise their voices above the hacking coughs and wheezing sounds. The first person to react to this abnormal situation was a group of prize-winning cattle that were about to be exhibited in London at the time. They had difficulty breathing and their tongues protruded. One of them died immediately, and the other 12 had to be sent to the slaughterhouse because of serious illness.

The weather in London on December 7th and 8th still did not improve. The smoke was terrible. The elderly and patients who have enjoyed the refreshing breeze from the north for several days now find it very difficult to breathe in this polluted air. Even some young people feel uncomfortable. People with respiratory diseases find it even more difficult to breathe in the polluted air. Get oxygen. For asthma sufferers, the smoke is a form of torture. London's hospitals were overwhelmed with patients, victims of the smog, and many died from it.

On December 9, the weather improved slightly. The fog remained, but the wind continued to blow gently from the south. Some clean air mixes with the smoke, diluting the original smoke. The temperature at noon was 3°C and the relative humidity was 95%.

On December 10, a cold front passed through England. A brisk westerly wind brings North Atlantic air. People's lungs breathed in fresh and clean air again. At this time, everyone sighed and felt relieved. Thinking back on those five days (including December 9), it was like having a nightmare.

According to subsequent statistics, the number of deaths in the four days during the smog period (December 5-8) was about 4,000 more than the same period in normal years. The highest number of deaths is among those over 45 years old, about three times the usual number; the number of deaths among children under 1 year old is about twice the usual number.

The number of deaths due to bronchitis, coronary heart disease, tuberculosis and heart failure in the week after the incident was 9.3 times, 2.4 times, 5.5 times and 2.8 times higher than the number of similar deaths in the week before the incident, respectively. Mortality rates for patients with pneumonia, lung cancer, influenza, and other respiratory diseases have doubled.

In addition to deaths, there are tens of thousands of people whose condition has greatly worsened, and there are also some people who have respiratory diseases caused by this. These people have not been counted. In addition, the number of victims should also include the sick and relatives of the deceased. Although they survived, their lives were changed by the losses they suffered. In any case, this must be considered a catastrophe.

The occurrence of huge smog in London is because the humid and foggy air is stagnant over the city, and the temperature increases inversely. The inversion layer is at a low altitude of 40 to 150 meters, and a large amount of smoke is sprayed into it, causing the smog to rise. Keep accumulating. The atmosphere over London became a dumping ground for the shredded waste from factories and household chimneys. Subsequent investigation data showed that the dust particle concentration was as high as 4.46 g/L, 10 times the usual level; sulfur dioxide was as high as 1.34 μg/L, 6 times the usual level. The ferric oxide in the smoke causes the oxidation of sulfur dioxide to produce sulfuric acid foam, which condenses on the smoke to form acid mist.