Air quality in Cuernavaca

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

Cuernavaca is the capital and largest city of the state of Morelos in Mexico. The city is located around a 90-minute drive south of Mexico City.

Looking back at the figures for 2020, it can be seen that Cuernavaca experienced a period of “Moderate” air quality with a US AQI reading of 55. This United States Air Quality Index number is calculated by collecting data from the six most commonly occurring air pollutants which are usually; nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide and both sizes of particulate matter, which are PM2.5 and PM10. This can then be used in comparison when studying other cities from any location. If not all six figures are available, a figure can still be calculated by using what data is available. In the case of Cuernavaca, the only figure recorded was for PM2.5 which was 14.2 µg/m³. This level is just under one and a half times the recommended target figure of 10 µg/m³ which is suggested by the World Health Organisation (WHO).

With air pollution at this level, the advice, therefore, would be to close doors and windows to prevent the ingress of more polluted air. Those who are sensitive to poor air should try to remain indoors as much as possible until the air quality improves. For up-to-date information as to the state of the air, there is a downloadable app from AirVisual which is available for all operating systems.

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

The figures published for 2020 indicate that the worst air quality occurs in April and May when the recorded figures were 36.0 and 37.8 µg/m³, respectively. These figures fall into the “Unhealthy for sensitive groups” category with readings between 35.5 and 55.4 µg/m³. The next category occurred in February and March, June and also in September, October, November and December. This category was classed as being “Moderate” with figures between 12.1 and 35.4 µg/m³. For the remaining three months of the year (January, July and August) Cuernavaca achieved the target figure as recommended by the World Health Organisation (WHO). This figure is 10 µg/m³ or less. Overall, January provided the best air quality whilst May provided the worst.

Records pertaining to air quality were first kept in Cuernavaca in 2019 when the annual mean reading was 22.8 µg/m³ which placed it as being “Moderate”. A slight improvement was noted for 2020 when that figure was 19.6 µg/m³. This figure coincided with the COVID-19 pandemic when many vehicles were no longer in daily use in an attempt to stop the spread of the virus. Many factories and non-essential production units were also required to close which removed their emissions from the atmosphere and therefore, most cities revealed very good figures for air quality.

Where does the air pollution come from in Cuernavaca?

The constant growth of the population in urban areas has brought with it the concentration of economic and productive activities, which under certain circumstances exacerbate problems such as those related to poor air quality. In particular, exposure to polluted air has important social and economic implications, perhaps one of the most relevant being that it is the leading environmental cause of premature death worldwide. According to the World Health Organisation, in 2012 air pollution was responsible for 3.7 million deaths on the planet (11% from chronic obstructive pulmonary disease, 6% from lung cancer; 40% from ischemic heart disease, 40% from stroke, and about 3% from acute respiratory infection).

Motor vehicles are the main source of the emissions of nitrogen oxides (NOx) and carbon monoxide (CO) in this area. 10.7 per cent of households still use firewood or charcoal for cooking or heating, creating particulate matter in quantities that are harmful to health, and the industries in the area are the main source of sulphur dioxide (SO₂) emissions.

What can be done to improve the air quality in Cuernavaca?

The state of Morelos joined the UN's global Breathe Life campaign in 2018, which seeks to drastically reduce air pollution, an environmental problem that causes millions of deaths a year worldwide. Morelos will apply a management program to improve air quality, ProAire, which includes measures to reduce the main polluting emissions and exhaustive monitoring of air pollution indicators.

With this program, between now and 2027 Morelos aims to reduce fine particulate matter (PM10 and PM2.5) by 15 per cent and nitrogen oxides, volatile organic compounds and carbon monoxide emissions from fixed and mobile sources (in based on 2014 indicators). The ProAire system debuted in Mexico City in 1996 and is credited with drastic improvements in air quality in the Mexican capital.

The introduction of less polluting gasoline, inspection of gas stations, use of new construction machinery, gradual withdrawal of minibuses, differentiation in hybrid and electric vehicles are some other ways that have been introduced in an attempt to reduce air pollution in Cuernavaca.

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

Outdoor ambient air pollution is a broader term used to describe air pollution in outdoor environments. Poor outdoor ambient air quality occurs when pollutants reach concentrations high enough to negatively affect human health and/or the environment.

Exposure to high levels of air pollution can cause a variety of adverse health outcomes. Air pollution can increase the risk of respiratory infections, heart disease, stroke, and lung cancer. Both short-term and long-term exposure to air pollutants have been associated with adverse health impacts. The most severe impacts affect people who are already sick. Children, the elderly and the poor are most susceptible. The most harmful pollutants for health, closely associated with excessive premature mortality, are fine PM2.5 particles that penetrate deep into the lung ducts.

Particulate matter (PM) is the term for particles that are suspended in the air, such as dust, soot, smoke and aerosol. Large amounts of particulate matter are typically emitted from sources such as diesel vehicles, burning waste and crops and coal-fired power plants. Particles less than 10 microns in diameter (PM10) present a health problem because they can be inhaled and accumulate in the respiratory system.

Particles less than 2.5 microns in diameter (PM2.5) are called "fine" particles and pose greater health risks. Due to its small size (about 1/30 the average width of a human hair), fine particles can lodge deep in the lungs and pass into the bloodstream through the alveoli.