Qualité de l’air à Metepec

What is the current level of air pollution in Metepec city?

Metepec is a municipality in the State of Mexico in Mexico and can be found directly to the east of the state capital, Toluca. It is approximately 50 kilometres west of Mexico City. A census was conducted in 2005 which estimated the population to be approximately 206,000 inhabitants.

During September 2021, Metepec was experiencing a period of “Moderate” air quality with a US AQI reading of 66. The United States Air Quality Index number is calculated by collating the recorded levels of six of the most prolific air pollutants. These may include, both diameters of PM (PM10, PM2.5), nitrogen dioxide, sulphur dioxide, ozone and carbon monoxide. But if figures are not available for all six, a level can still be calculated by using what information there is. It can then be used as a metric when comparing one city with another, anywhere in the world. The only figure available here was that of PM2.5 which was 19.2 µg/m³. This figure is almost twice the target figure as recommended by the World Health Organisation (WHO). They suggest a ceiling limit of 10 µg/m³ although no amount of air pollution is safe.

Although this level is not really high, the advice would be to stay indoors as much as possible, closing doors and windows to prevent the ingress of more dirty air. Those of a sensitive disposition should avoid all outdoor activity until the air quality improves. If venturing outside is unavoidable, then a good quality face mask should be worn at all times. For up-to-date information about air quality, there is an app available from AirVisual which is downloadable for all mobile devices from your usual app store.

Does the level of air quality vary throughout the year?

Over the course of 2020, the air quality remained mostly the same without too much variation. All monthly figures fell into the “Moderate” category with readings between 12.1 and 35.4 µg/m³. The month with the best air quality was July with a 19.7 µg/m³ reading. The month with the worst was December with 33.8 µg/m³.

Historically, records regarding air quality were not kept before 2020 when a recording of 27.1 µg/m³ was noted. This reading may have been affected by the COVID-19 situation as many vehicles were no longer in daily use as staff were 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.

Is there a main source of air pollution in Metepec?

The pollutant that most frequently determines poor air quality in the region are PM10 (49% of the days of the year), followed by PM2.5 (38%) and ozone (9%).

The number of days in which at least one environmental health standard was breached, was 191, which is equivalent to 52 per cent of the days of the year.

This statistic is a good indicator of the severity of the air quality problem in the region, as it highlights that only 48 per cent of the days of the year were recorded pollution levels below the recommended limits for the protection of the health of the population.

Days with poor air quality due to ozone were present in all monitoring stations and their frequency of occurrence varied between 1 per cent of the days of the year in the San Mateo station (SM) and 7 per cent in Metepec (MT).

One of the factors that affects this, is the high vehicle registry, since there are many automobiles that circulate in the municipality and the metropolitan area allows a large amount of gas to be emitted.

What can be done to reduce air pollution in Metepec?

Use public transport and use a private car only when absolutely necessary. Alternatively, you can share private cars between several people. The fewer cars, the less emissions. And any movement that can be made by bicycle or on foot is less polluting than any car.

Specific actions included the removal of lead from gasoline, the implementation of catalytic converters in automobiles, the reduction of sulphur in diesel fuel, substitution of fuel oil in industry and power plants with natural gas, reformulation of liquefied petroleum gas for cooking and heating, reinforcement of vehicle inspection and maintenance program, and implementation of “no driving day (Hoy No Circula)” rule.

As a result of these emissions reduction measures, concentrations of criteria pollutants have been decreasing over recent years.

What are the health impacts of breathing dirty air in Metepec?

Specialists have catalogued all these particles based on their size. Thus the "PM10" are particles that measure one ten thousandth of a millimetre, (such as pollen, viruses and bacteria), and can "be trapped" in the nose, mouth, and the area of the laryngopharynx, while the particles " PM2.5” are one hundred times thinner than a human hair and penetrate to the pulmonary alveoli.

The really serious issue is that PM2.5 have organic compounds and heavy metals adhered to them, and are "100 per cent breathable", even managing to reach the bloodstream. Hence, its effect on human health is more harmful, and is often associated with heart disease, asthma attacks, premature death in people with lung and heart problems, and even cancer.

Many residents will experience some type of symptoms related to air pollution, such as watery eyes, coughing or noise when breathing and even skin irritation can be attributed to polluted air. Even for healthy people, polluted air can cause irritation or breathing difficulties during exercise or outdoor activities. Your actual risk depends on your current health, the type and concentration of the pollutant, and the length of time you have been exposed to the polluted air. Some groups of people are more susceptible to dirty air than others, such as those with pre-existing respiratory problems, pregnant women, children under the age of 14 years, elderly residents whose immune system is not as strong as it once was. Those whose jobs dictate that they spend long periods of time outside and those who choose to exercise outside are also more prone to suffer from the effects of dirty air.