Air pollution in Mexico City

Problems

• Air pollution in Mexico City

  One of the current environmental hotspots is Mexico City. The situation in this city reached a critical point back in the 20th century and has changed only slightly for the better since then. Besides all the existing environmental problems, such as pollution and lack of fresh water, insufficient access to it and its poor quality; deforestation; soil erosion; desertification; deterioration of agricultural land; pollution, and subsidence of the ground, the most basic and acute is the problem of air pollution in Mexico City.
  
  Clean air is not only a luxury but an essential need for everyone. Air pollution is a real problem in Mexico, causing about one in 17 (5.9%) of all deaths in the country. The most dangerous airborne particles are known as PM 2.5 (particles less than 2.5 thousandths of a millimeter across), which can penetrate deep into the lungs.
  
  To fully understand the catastrophe and the level of air pollution in Mexico it is enough to remember that living in Mexico City and just breathing the air is equivalent to smoking 2 packs of cigarettes a day. And this is the capital of Mexico with a population of more than 22 million people. In the early 1990s, the environmental situation in the city was so bad that about 1,000 residents died a year for this reason, and more than 35,000 ended up in medical facilities.
  
  Several reasons led to this disastrous situation in the city. Mexico City experienced industrialization and urbanization in the 20th century, and the population of the Mexico City Valley metropolitan area, also called Greater Mexico City, grew significantly from 3.1 million people in the 1950s to 14 million in the 1980s. Rapid population growth, an increased workforce, and human activity have led to a dramatic deterioration in air quality. These air pollutants are mostly produced by human activities such as the burning of fossil fuels in power plants and automobile exhausts.
  The densely populated capital has more than 4 million cars and a large number of industrial plants, resulting in dirty smog enveloping the city. Along with microscopic particles, automobile and industrial emissions of greenhouse gases - carbon monoxide, sulfur dioxide, nitrogen oxides, and ozone - are the main sources of air pollution in Mexico City. Mexico ranks first in Latin America for carbon dioxide emissions, caused by the inefficient use of energy in industry and transportation. Liquid and solid particles from automobile and industrial emissions, fires, soot, and dust are difficult to remove from the atmosphere and have hazardous effects on human health.
  
  Mexico city's air pollution problem is also caused by the geographical location of the city. It is surrounded by volcanoes more than 2 km above sea level, plus the hot climate - all these factors lead to increased air pollution.
  The Mexico City metropolitan area consists of the city proper and the surrounding states and cities in the Mexico City Valley. About 21 million people live at an altitude of 2,240 meters on a plain surrounded by mountains, in the crater of an emission-absorbing ancient volcano. The low oxygen content characteristic of such an altitude reduces the efficiency of car engines, resulting in more pollutants being emitted than elsewhere. Moreover, the warm air over the valley, the so-called "inversion layer," traps pollutants over the metropolis. In addition, the city sits at the bottom of a dried-up lake, during rains some areas of the capital are flooded.
  
  The reasons why the air quality in Mexico City is so bad are as follows.
  ×        Forest fires
  ×        Automobile emissions
  ×        Industrial emissions
  ×        Surrounding mountains that do not allow pollutants to escape
  
  1. Forest fires.
  The dense cloud of toxic air in Mexico City's atmosphere is the main result of dozens of forest fires burning in southern Mexico and Central America. Because of the wildfires, pollution levels in the city are above critical levels.
  There have been long dry and high-temperature seasons recently. This has resulted in wildfires. Because of this, the air quality in the city is getting so bad that local authorities are urging people to stay indoors because the air outside is not safe to breathe.
  
  2. Аutomobile emissions
  The most important air pollutants in Mexico City are ozone, sulfur dioxide, nitrogen dioxide, hydrocarbons, and carbon monoxide, mainly caused by automobile exhaust.
  The main culprits are cars that use combustible fuel. About 8 million cars are traveling in the Mexican capital every day, and it is estimated that they produce more than 7,000 tons of pollution in Mexico City every day. This, in turn, creates smog.
  
  3. Industrial emissions
  Fossil fuels (coal, oil, and natural gas) are the main source of energy in Mexican factories, but the use of fossil fuels causes pollution. When they burn, chemicals and gases are released into the air.
  These primary pollutants can cause many problems from irritating people's eyes and throats to global warming.
  Primary pollutants include carbon monoxide, nitrogen oxide, sulfur oxides, and particulate matter such as dust, ashes, etc. In addition to being dangerous on their own, when exposed to the sun, many primary pollutants react photochemically to produce secondary pollutants such as nitrogen dioxide, sulfuric acid, and ozone.
  
  4. Surrounding mountains that prevent pollutants from escaping
  Mexico City's unique geographical structure allows carbon monoxide pollutants to linger in the air. Mexico City is surrounded by mountains, making it appear to be trapped by high walls of mountains.
  This makes the city look like a swimming pool, hence the popular phrase, Mexico City's air basin. Because of the structure of the land, the winds cannot carry smog over the surrounding mountains, and as a result, many pollutants, such as carbon monoxide, accumulate over the city.