Clouds of murder

In the past 30 years, in the 20th century, the United States, Britain, and Japan have in turn killed murderers, causing great losses.

Before the 1960s, the world also had 8 major harms, of which smoke accounted for 5 cases, many people suffered accidents, the scope of influence was very wide. The most typical is the smoke in London (UK) and the chemical smoke Los Angeles (USA). They represent two different types of smoke. Cloudy London cloud is oxidized smoke - reduced causing mainly by oxygen sulfide compound. Los Angeles cloud cloud is photochemical smoke mainly caused by old oxygen and ozone.

In certain geographical and weather conditions, air pollutants will gather in a certain area . The cloud of smoke Cloud cloud of London - December 5-8, 1952 killed 4,000 people within 4 days (Photo: pyr.ec.gc.ca) London formed in that case. London is a large city with a history of over 2000 years, located in the wide delta of the Thamesa River. From December 5-8, 1952, the ground of London was not windy, at that time it was winter, the air temperature was very low, wet and the air pressure was heavy in the sky, causing London to be clouded for several days. dense blind cover does not see the sun . Thousands of thousands of chimneys still release smoke into the sky, thick black smoke columns, smoke dust concentration is 10 times higher than normal, concentration of SO ₂ is 6 times, Fe ₂ O ₃ in smoke works with CO2 in the air creating foam H ₂ SO ₄ , condensing in smoke and dust into acid clouds. Over 4 days killed more than 4,000 people . Two months later, almost 8000 people died. At that time, people did not know the cause, so there was no cure and prevention. In 1957 and 1962 London again occurred the cloud of murder . The British government compared two smoke cases in 1952 and 1962 to find the cause of harm.

Photochemical smog is formed in a certain weather condition under the photochemical reaction of air pollutants . It is formed in conditions of sufficient light, sufficient concentration of nitrous oxide and hydrogen carbon and geographic conditions, climate is not convenient to diffuse such polluted gases. The case of death because of smoke in Los Angeles has met these three conditions, so it caused photochemical clouds .

Los Angeles in the 40s of the 20th century had more than 2.5 million cars, automobile smoke was the cause of photochemical reactions (Photo: bardaglea) Los Angeles is an industrial city, located in a basin 50km long face overlooking the sea, back against the mountain. In the early 40s of the twentieth century, Los Angeles appeared a light blue cloud of smoke, a few days of insolvency, causing people here to have symptoms of sore throat, eye pain, sneezing, headache, nausea. After a long period of investigation until 1951, this type of smoke was discovered by the exhaust of cars. Now in Los Angeles there are more than 2.5 million cars, digesting 16,000 liters of gasoline every day. These cars release carbon monoxide and carbon nitrous oxide compounds. Because the summer and early fall in Los Angeles are bright sunshine, under the effect of sunlight, photochemical reactions occur with substances in automobile smoke, forming photochemical smoke with mainly O ₃ . This type of smoke has caused the above symptoms, in case of suffering, it makes breathing difficult, vision loss and paralyzed limbs. If a long-term victim can harden the artery and reduce physiological function.

Currently, in cities where many cars are concentrated, it is always threatened by photochemical cloud, lack of effective measures to prevent.