Some of the big cities in the U.S. still have smog?

Which city is the most smoggy? The topography of Xi'an is high in the north and low in the south, and the south is because of the barrier of the Qinling Mountains, the pollutants are not easy to diffuse after they are formed, and they will gather in the urban area and not easy to disperse. People who live in Xi'an also know that there are fewer winds in Xi'an throughout the year, and the cold air is not very active, which is also detrimental to the diffusion of pollutants.

We all know that the ridicule is that the control of haze mainly depends on blowing, and this blowing I think is the dispersing power of wind and cold air. In addition, Xi'an is located in the northwest, and further northwest along the Hexi Corridor will reach Ningxia and Gansu, where there are many sandstorms, and the dust will also spread to Xi'an along the Hexi Corridor.

There are many industrial enterprises gathered around the urban area of Xi'an, and the dust pollution caused by winter construction, some people joke that Xi'an people love to eat oil and splash noodles, which will also cause an increase. In short, the superposition of all these unfavorable factors has made Xi'an's smog more serious, and our intuitive feeling is that Xi'an's smog days this year seem to be more serious than last year. Geographical environment.

Fog and haze are twins, and their formation requires cold, humid and windy natural conditions. Xi'an is located at the northern foot of the Qinling Mountains, a typical northern city, with cold winters; The rainy season is concentrated in autumn, with continuous autumn rains, low evaporation, and a lot of water accumulated in the soil; Although the northwest wind prevails in winter, it is blocked by the Qinling Mountains and the circulation is not smooth.

Topographic factors. The Guanzhong Plain is bordered by the Qinling Mountains in the south, the Loess Plateau in the north, and the mountains and hills in the east and west, with low-lying terrain and weak winds, and the surrounding pollutants are easy to be blown into the sediment by the wind, but not easy to discharge. Xi'an is an important national defense industrial base, the urban area is full of high-rise buildings, the surrounding thermal power plants, heavy industry, building materials industry more, coupled with winter central heating, coal consumption is larger, natural gas combustion is insufficient, and it is easy to emit exhaust gas, waste gas, rural firewood and grass boiling water for cooking, winter coal heating, breeding pollution, garbage dumping is also a reason, but compared with industrial pollution, waste gas, waste water and waste discharge, etc., the impact should be minimal.

High-rise buildings are dense and poorly ventilated, resulting in hot summers (urban heat island effect) and smog in winter.

The cities with more serious smog are Beijing, Tangshan, Fushun, Dalian, Baoding, Shijiazhuang, etc., which should be for the development of industry and exhaust emissions, resulting in serious haze and serious air pollution.

I think it's Shijiazhuang, Hebei Province, because Hebei Province itself is an industrial province, and Shijiazhuang is the capital of this province, so the air pollution will be more serious.

Beijing, of course. Beijing is the political, economic and cultural center of our country, so it is inevitable that there will be many enterprises and a lot of vehicle exhaust emissions.

It's Tianjin, and the smog in this place is very serious, and there is a long time every year, and the air environment is very bad.

It can be determined that most areas do not have it, because the United States developed industry very early, and the industry in the United States was already very mature when the Qing Dynasty smoked big smoke, so the United States has also experienced decades of haze, and the development of industry will definitely affect the air, which is certain.

In order for a country to develop, it must be dominated by industry, and if there is industry, there will be production, and if there are production factories, it will produce smog and other substances that pollute the air and the environment, and this will form smog after that.

Big cities, such as Los Angeles in the 70s, had them, but now they are long gone.

There will definitely be, but it won't be like we don't control and govern!!

In the 70s of the last century, the environment began to be regulated, none.

Just like China is now. Because the factories have moved to China.

Once London was famous, now there are almost no more developed countries. The one in San Francisco is fog, not dust.

Of course, there is, but the severity of smog varies from country to country.

There is smog abroad, but they manage it well.

After the earliest industrial revolution in Britain, the chimneys of factories in the London area were densely packed, burning coal day and night, bringing a large amount of dust and toxic gases, making 1 4 days of the year covered in fog, so it was called the "fog capital". In 1952, more than 10,000 people died in the five-day "smog".

In 1956, the United Kingdom promulgated the "Clean Air Act", which was mainly based on reducing the amount of coal, and the United Kingdom was the first to renovate the traditional stoves of urban residents on a large scale, and adopt central heating in winter, and relocate large coal-burning power plants and heavy industry to the suburbs. By the 80s of the 20th century, the focus of pollution control in Britain was the treatment of automobile exhaust. **Require all new cars to be equipped with catalysts to reduce nitrogen oxide emissions, and impose sky-high entry and parking fees for private cars to control the flow of private cars.

At the same time, we will vigorously promote new energy vehicles, public transportation and green transportation. Strengthening greening is also an important means to control air pollution. In densely populated London, the per capita green area is as high as 24 square meters, and there are also large circular green belts built on the periphery of the city, covering an area of thousands of square kilometers, almost three times the area of the city.

Today, in London, foggy weather has been reduced from 90 days a year more than 100 years ago to less than 10 days. The UK's experience in pollution control is, to a certain extent, representative of the attitude of European countries. For example, bicycles replace car travel, which has also been advocated and implemented in the Netherlands, Denmark and other countries.

As the most developed country, the United States has caused serious air pollution due to industrial emissions, automobile exhaust, etc. In the mid-20th century, the concentration of ozone in the atmosphere in the Los Angeles area was very high, and the problem of photochemical smog was prominent, which led to the tragic death of hundreds of elderly people in just a few days in 1952 and 1955.

The U.S. has adopted a regional environmental management framework that breaks down state boundaries and conducts unified management. Environmental protection agencies have the right to legislate, enforce and impose penalties, and coordinate their work through a combination of enforcement and monitoring and technological improvements. In 1990, amendments to the Clean Air Act were passed, and in 1997 the EPA established standards specifically for atmospheric content to better detect such fine particulate matter, which was previously overlooked.

When pollution is severe, U.S. officials will ask people to control the intensity and duration of outdoor activities to reduce physical damage. In addition, the public is advised not to exercise near busy roads, not to smoke indoors, to reduce the use of candles, and to burn wood stoves to control indoor pollution. In the United States, the air pollution control method, particularly worth mentioning is the emission rights trading, under the condition of the total pollutant emission control index, the use of market mechanism, the establishment of legal pollutant emission rights, that is, the right to discharge, and allow this right to be bought and sold like a commodity, so as to control the emission of pollutants, so as to achieve the purpose of reducing emissions and protecting the environment.

The smog is so severe, what about housing prices in those cities that don't have smog?

Beijing, Nanjing. Xi'an is more obvious. If you want to filter the haze in less than microns. Then you can only use the Hydra Antibacterial and Antiviral Mask Filter: nanofiber filter layer, granular activated carbon filter layer, nano sterilization, super protection.