Introduce world famous cities

Paris is a real flower. It is no exaggeration to call it "Huadu". Whether on the dining table, on the balcony, in the courtyard, in front of the window, on the street, in people's arms, the eyes are full of blooming flowers, and the air is filled with intoxicating fragrance. There are also colorful flower shops and colorful parks, which make people linger. This is a city with a history of more than 2000 years. This was once the birthplace of French bourgeois revolution and proletarian revolution. 1789, 14 In July, the revolutionary masses in Paris conquered the Bastille, which started the French bourgeois revolution. July 14 was therefore designated as the French National Day. 187 1 08 March 18, the working class in Paris held a revolutionary armed uprising that shocked the world and established the Paris commune, the first proletarian regime in the world. Paris is also a city with high cultural taste. It has many cultural relics and historical sites, including more than 3,000 protected ancient buildings, many of which are still well preserved. Walking into Paris is like walking into an architectural museum, a cultural palace and an art treasure house. Walking on the streets of Paris, whether in the narrow lanes of Montmartre or on the grand Champs Elysé es, you will often encounter historical sites and artistic buildings that you have admired for a long time: Louvre, Palace of Versailles, Place de la Concorde, and more importantly, the Arc de Triomphe, Notre Dame de Paris, Paris Opera House and Eiffel Tower.

Fog no longer-the history of air pollution control in London

As early as the Middle Ages, the problem of soot polluting the atmosphere began to appear in London. At that time, the British Parliament also issued a decree prohibiting craftsmen from using coal during the parliamentary session. After the industrial revolution supported by coal began, because most factories were built in cities, residents burned a lot of coal to keep warm, and the smoke and dust emissions increased sharply. In the windless season, smoke and fog turn yellow and black, often hovering over the city for many days, forming the London fog described by Mr. Lao She, who once lived in London, as "black, muddy yellow, crimson, spicy and choking".

Tourists who love British culture may temporarily indulge in the hazy scenery of the foggy city, but Londoners who have lived here for a long time are deeply troubled by it. Dense fog will hinder traffic, and high concentration of sulfur dioxide and smoke particles will endanger the health of residents. Therefore, Britain passed the public health bill in 1875 in an attempt to reduce urban pollution. In the 1920s, due to the government's strengthening of industrial management, the proportion of coal in industrial fuel decreased, and the smoke pollution was reduced, but there was no qualitative improvement.

1952 65438+On February 4th, the cold high pressure over London caused the atmospheric humidity to increase, and the wind was weak, making it difficult for pollutants to spread. The suffocating smog filled the city for five days, and the death toll increased by 4000 in a few days. This is the famous "London fog" incident. The data show that the peak of death is basically consistent with the peak of dense fog of sulfur dioxide and smoke. Similar smog disasters happened several times later, which caused great shock to the British people.

1956, the British government promulgated the Clean Air Act for the first time, which reformed the traditional stoves of urban residents on a large scale and reduced coal consumption. Adopt central heating in winter; Set up smoke-free areas in cities and prohibit the use of fuel that produces smoke; Power plants and heavy industrial facilities, which are the main pollution sources of smoke and dust, have been moved to the suburbs. 1968, the Clean Air Law was promulgated, requiring industrial enterprises to build tall chimneys and strengthen the evacuation of air pollutants. 1974 promulgated the air pollution control law, which stipulated the upper limit of sulfur content in industrial fuels. These measures have effectively reduced the smoke and sulfur dioxide pollution caused by coal burning. In 1975, the number of foggy days in London decreased from dozens of days a year to 15 days, and from 1980 to 5 days. Fog has lost its name.

However, the story does not end here. Since 1980s, more and more cars have replaced coal as the main air pollution source in Britain. At first, people mainly paid attention to the influence of lead pollution in gasoline on human health, and unleaded gasoline was gradually paid attention to. By the end of 1980s and the beginning of 1990s, other pollutants emitted by automobiles, such as nitrogen oxides, carbon monoxide and unstable organic compounds, have also become the object of close attention. These substances undergo complex photochemical reactions under the action of solar ultraviolet rays, producing a variety of secondary pollutants mainly ozone, which is called "photochemical smog".

From 1993 to 1, all new cars sold in the UK must be equipped with catalytic converters to reduce nitrogen oxide pollution. 1995, Britain passed the environmental law, requiring the formulation of a national strategy to control pollution. The latter was promulgated in March, 1997. According to the standards of China, the European Union and the World Health Organization, it has set a quantitative goal of pollution control that must be achieved before 2005, requiring industrial departments, traffic management departments and local governments to work together to reduce the emissions of eight common pollutants, such as carbon monoxide, nitrogen oxides and sulfur dioxide.

200 1 1 30, the city of London released the draft air quality strategy. Mayor ken livingstone said that every year, 24,000 people in Britain die from diseases related to air pollution, and he will devote himself to further improving the air quality in London and eliminating the impact of air pollution on public health and daily life. At present, the content of inhalable particulate matter and nitrogen oxides in the atmosphere of London is still higher than the maximum content stipulated by the national air quality target. These pollutants mainly come from transportation. The municipal government will vigorously support public transportation, with the goal of reducing the traffic flow in the city center by 10% to 15% by 20 10. London will also encourage residents to buy cars with low exhaust emissions, and promote efficient and clean engine technology and low-pollution cars using natural gas, electricity or fuel cells.

Now people who come in the name of Muwucheng may be disappointed. They only occasionally see a thin layer of white fog in winter or early spring morning, and the yellow fog described in countless English literary works is rolling in the street and has disappeared. After the sunshine dispelled the mist, it was clear all around, making it difficult to imagine the foggy scene. For London, it may be less mysterious and romantic, but it has gained a higher quality of life. How important it is to live in a clean and healthy environment!