Air quality in Leon

Is Leon a much polluted city in Mexico?

León is the most populous city and the municipal seat of the municipality of León in the Mexican state of Guanajuato. According to a 2020 census, Leon had an estimated population of approximately 1,722,000 people. This figure ranks it as the fourth most populous municipality in all of Mexico.

Looking back at the figures published for2020 by IQAir .com, it can be seen that Lean was experiencing a period of “Moderate” quality air with a US AQI reading of 59. This United States Air Quality Index number is calculated using the levels of six of the most prolific air pollutants, such as nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide and both sizes of particulate matter, being PM2.5 and PM10. It can be used as a standard when comparing air quality in other cities around the world. If data is unavailable for all 6 pollutants, a figure can still be calculated by using what figures there are. In mid-August 2021, there were five recorded levels of the different pollutants. PM2.5 registered 16 µg/m³, PM10 was 26 µg/m³, next was ozone (O₃) with a figure of 0.1 µg/m³, but nitrogen dioxide (NO₂) and sulphur dioxide (SO₂) failed to register a level.

The given advice would be to close all doors and windows to prevent more polluted air entering the premises and those of a sensitive nature should avoid going outside until the air quality is better. The table that is published on this website may help inform you, or download the mobile app from AirVisual to get the latest information about air quality in real-time.

Does the level of pollution stay the same throughout the year in Leon?

On reviewing the published figures from 2020, it can easily be seen that the quality of air did not vary too much over the course of the year. The figure was “Moderate” over the whole 12 months. To be classified as “Moderate” the figures must fall between 12.1 and 35.4 µg/m³. June, July, August and September recorded the best air quality.

Historically, records pertaining to air quality have been kept since 2017 when a “Moderate” figure of 27.3 µg/m³ was registered. The following year saw an improvement with a 20.8 µg/m³ reading with a similar one of 20.9 µg/m³, the following year. Another improvement was seen for the following year of 2020 with a 19.0 µg/m³ reading.

This improvement coincided with the COVID-19 pandemic, many vehicles were no longer in daily use in an attempt to halt the spread of the virus. Some smaller factories and non-essential production units were also required to close which removed their emissions from the atmosphere.

Where does the air pollution come from in Leon?

The municipality has a population of 1,436,733 inhabitants and concentrates 27.7 per cent of the total vehicle fleet in the state of Guanajuato and the most important footwear industry in Mexico is also established there, which is reflected in an environmental deterioration. Environmental pollution in León is considerable, since 57.2 per cent of the surveyed population states that the air quality is bad. This situation is reflected in the environmental deterioration and health problems of the city's inhabitants.

The large vehicle fleet is the main emitter of carbon monoxide but it is the second place to emit total organic compounds (TOC), derived from the tanning processes and the use of solvents, coatings and glues used by the tannery and footwear industry.

Can anything be done to reduce air pollution in Leon?

Regarding pollution, politicians have established some programs trying to improve air quality in Mexico. Regarding pollution, the capital of Mexico is one of the most polluted cities in the world. Mexico City is ranked as the number 5 of the world’s dirtiest cities. This is the result of industrial and automobile emissions that affect the air quality and these emissions cause higher levels of sulphur dioxide, nitrogen oxide, carbon monoxide, fine particulate matter and organic compounds like benzene. Some compounds like nitrogen oxide and volatile organic compounds cause air pollution problems in stagnant air, as the reaction between these elements forms ozone and other oxidants. Ozone and particulate matter are the most serious pollutants in developing and developed countries. Similar problems also occur in Leon.

A low emission zone stops the more polluting vehicles travelling in an area and reduces pollution. Low emission zones can have a significant impact on air pollution. However, they often do not solve the problem alone and other measures are often also needed.

Measures to reduce the amount of traffic and measures to improve and encourage other travel options. These include good, clean public transport, good cycle facilities, low emission car sharing schemes and appropriate town planning.

Emergency traffic restrictions in times of high pollution, for example banning all or specific vehicles, diesel bans, allowing only alternating number plates on odd or even days are some tried and tested ways of reducing air pollution in the city centre.

Incentives for cleaner vehicles. For example reduced road tax, cheaper road tolls, grants for electric or hybrid vehicles, cheaper or available parking are other methods to be considered.

As for other measures the introduction of emissions control of factories and power stations and controls on construction sites. For example reducing demolition dust, using cleaner fuels, newer vehicles and fitting equipment like diesel particulate filters on diesel construction machines.

What are the detrimental effects of air pollution in Leon on our health?

The main components of suspended particles (PM2.5 and PM10) are: sulphates, nitrates, ammonia, sodium chloride, coal, mineral dust and water. PM consists of a complex mixture of liquid and solid particles of organic and inorganic substances suspended in the air. Particles are classified according to their diameter into PM10 (particles with a diameter less than 10 microns) and PM2.5 (diameter less than 2.5 microns). The latter poses a greater danger because, when inhaled, they can reach the peripheral areas of the bronchioles and alter the pulmonary gas exchange.

They are the only ones capable of reaching the alveoli and can therefore cause respiratory problems. According to the WHO, chronic exposure to the particles increases the risk of cardiovascular and respiratory diseases, as well as lung cancer.

Excess ozone in the air can have serious adverse effects on human health. It can cause breathing problems, cause asthma, reduce lung function, and lead to lung disease. It is currently one of the atmospheric pollutants of greatest concern. Various studies have revealed that daily mortality and mortality from heart disease increase by 0.3 per cent and 0.4 per cent respectively with an increase of 10 µg / m³ in ozone concentration.

In high proportions it is detrimental to health. It is considered very dangerous in concentrations higher than 0.1 ppm for one hour, it produces an accelerated calcification in the bones of the human body and affecting the same, the vision, respiratory and circulatory systems and can damage the Central Nervous System.