Qualité de l’air à Irapuato

Is Irapuato currently a very polluted city?

Irapuato is a Mexican city (and municipality) located at the foot of the Arandas Hill, in the central region of the state of Guanajuato. It lies in an area between the Silao River and the Guanajuato River, and is the second largest city in that state. According to a census conducted in 2010, Irapuato had an estimated population of approximately 381,00 people in the city but this number swelled to 530,000 when the metropolitan area was included. At the beginning of 2022, Irapuato was going through a period of “Moderate” air quality with a US AQI reading of 75. This United States Air Quality Index number is an internationally used set of metrics supported by the World Health Organisation (WHO) and is used to compare the air quality in different cities throughout the world using comparable standards. It is calculated by using the levels of the six most commonly found pollutants such as nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide and both sizes of particulate matter, which are PM2.5 and PM10. If all six figures are not always available in which case, a level is calculated by using what data there is. All six of the major pollutants were recorded in Irapuato. They were as follows; PM2.5 - 23.5 µg/m³, PM10 - 66 µg/m³, ozone (O₃) - 0 µg/m³, nitrogen dioxide (NO₂) - 0 µg/m³, sulphur dioxide (SO₂) - 0 µg/m³ and carbon monoxide (CO) - 1454.2 µg/m³.

This level of PM2.5 is just less than two and a half times above the recommended safe level of 10 µg/m³ as suggested by the World Health Organisation (WHO) as being an acceptable level. Although no amount of air pollution is considered to be safe.

When air pollution is classified as being “Moderate” the given advice would be to remain indoors as much as possible, closing doors and windows to prevent the ingress of more polluted air. Those who are more sensitive to poor quality air should avoid venturing outside until it improves. If this is unavoidable, then a good quality face mask should be worn at all times. All types of outdoor exercise should be avoided until the air quality improves. There is a downloadable app from AirVisual.com which is suitable for all operating systems and gives the latest information regarding air quality in real-time.

Does the level of air pollution vary much throughout the year in Irapuato?

Air quality can be affected by many things, therefore it can and does change rapidly depending on the local conditions. Looking back at the 2020 figures published by IQAir.com, it can be seen that the two cleanest months of the year were August and September when the quality of air was “Good” with figures between 10.1 and 12.0 µg/m³. The rest of the year saw air quality classed as being “Moderate” with readings between 12.1 and 35.4 µg/m³. The dirtiest month of the year was April with a level of 24.1 µg/m³.

Historically, records pertaining to air quality have been held since 2017 when the annual average was noted to be 23.2 µg/m³. The year after saw a marked improvement with a figure of 19.7 µg/m³ which was followed by a small improvement during 2019 with a reading of 19.2 µg/m³. The most recent available figure is from 2020 and was 18.2 µg/m³. This lower figure was almost expected because it would have been affected by the COVID-19 pandemic as many vehicles were no longer in daily use because the offices were closed and the staff encouraged to work from home, in an attempt to halt the spread of the virus. Many factories and non-essential production units were also required to close which removed their emissions from the atmosphere, albeit on a temporary basis. Worldwide, cities reported a much better quality of air due to the general lack of traffic pollution in city centres due to the pandemic.

Where does all the air pollution come from in Irapuato?

Salamanca and Irapuato present, once again, high levels of sulphur dioxide concentration. The high levels of pollutant concentration are due to the use of fuel oil in the production processes of the Salamanca Thermoelectric Power Plant and the Engineer Antonio M. Amor Refinery.

Volcanic activity, fires, dust and sand storms, and other natural events are responsible for circulating polluting particles in the atmosphere. However, humans also contribute directly to air pollution. During the burning of fossil fuels, the emissions generated favour the creation of atmospheric pollutants, ranging from sulphur dioxide and benzene to carbon monoxide and heavy metals.

Can anything be done to improve air quality in Irapuato?

Pollution from vehicles has important respiratory and cardiovascular effects on the population, especially children, people with chronic conditions and older adults. Carbon monoxide (CO) is the pollutant with the highest volume of emission from automobile exhaust. This has motivated local governments to implement verification programs.

Despite the fact that Irapuato went from having poor quality to unsatisfactory quality in its air, the Ministry of the Environment and Territorial Planning maintained the recommendation not to carry out outdoor activities and also urged citizens to reduce car use, as well as avoiding the burning of pastures, pyrotechnics or bonfires.

What are the detrimental effects of breathing in polluted air?

Air pollution is a global problem, but it does not affect everyone equally. In highly urbanized areas there are groups with greater vulnerability, for example all those who suffer from cardiovascular and respiratory diseases, the population sensitive and reactive to allergies that affect the respiratory tract, new-borns and the elderly.

The air we breathe is not clean. Ambient air contains invisible and visible particles, chemicals, and bacteria, among others. Our bodies have adapted to deal with some of these pollutants: our anatomy, from the nose and mouth to the various passageways through which air passes to reach the inner part of the lungs – where oxygen exchange and removal of carbon dioxide) – acts as a mechanical air filter. Despite this, various particles and gases that make up what we call "air pollution" will reach the inner part of the lungs.

On its way from the nose to the lungs, part of this polluted air will be trapped in different obstacles, such as the hairs in the nose or the bifurcation of the bronchi, but the rest will reach the lung cells. There, irritation will occur, since they are foreign bodies for our body, and our immune system will fight them, generating pulmonary inflammation that can be harmful.