Qualité de l’air à Mexicali

What is the current level of air pollution in Mexicali?

Mexicali is the capital city of the Mexican state of Baja California and seat of the Municipality of Mexicali. According to a census conducted in 2010, Mexicali had an estimated population of approximately 700,000 residents. Take into account the entire metropolitan area and the number swells to 937,000 people. This ranks it as the second most populous area in Baja, California.

Towards the end of 2021, Mexicali was going through a period of air quality that was classed as being “Unhealthy for sensitive groups” with a US AQI reading of 157. 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, which are PM2.5 and PM10. It can then be used as the metric 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 Mexicali, only PM2.5 was measured which was 67.7 µg/m³.

When air quality is this bad, the advice is to remain indoors as much as possible, closing all doors and windows to prevent more polluted air from entering. It is advantageous to use an air purifier if one is available but ensure it is set to recirculate the current air and not import more from outside. Those of a sensitive disposition should also avoid venturing outside until the air quality improves. If this is unavoidable, then a good quality face mask should be used at all times. There is an app available from AirVisual.com for most mobile devices which informs the user of the quality of air in real-time which should assist with the decision as to whether go out or not. It is free of charge.

Does the level of air pollution fluctuate throughout the year in Mexicali?

Air quality is very volatile as it can be influenced by many external factors such as meteorological and atmospheric.

Looking closely at the figures released by IQAir.com for 2020, it can easily be seen that for three months of the year, Mexicali achieved the target figure as recommended by the World Health Organisation (WHO) of 10 µg/m³ or less. These were the months of May, July and August with respective figures of 8.6, 9.4 and 10 µg/m³. The months of March, April and June saw figures from the “Good” category with readings between 10.1 and 12 µg/m³. The four months of February, September, October and November saw air quality from the “Moderate” sector with readings between 12.1 and 35.4 µg/m³. the remaining two months of January and December saw poor air quality from the “Unhealthy for sensitive groups” category with readings between 35.5 and 55.4 µg/m³.

Records were first kept in 2017when a figure of 22.7 µg/m³ was noted. A sharp deterioration was recorded in 2018 when the figure was 30.2 µg/m³. The next year showed a considerable improvement with a figure of 17.7 µg/m³ but then declined again in 2020 to 19.7 µg/m³. However, this reading may have been affected by the COVID-19 pandemic as many vehicles were no longer in daily use because the offices were closed, 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.

Is there a main source of air pollution in Mexicali?

Mexicali is the most polluted city in the country and North America. According to data from the 2018 World Air Quality Report, Mexico City ranks 10^th in the country in terms of cities with poor air quality due to the presence of polluting particles, registering 19.7 micrograms of particles in 2018 fines per cubic metre. Pollution levels in the municipality of Baja California exceed twice those recommended by the World Health Organisation (WHO), according to data from the World Air Quality Report 2018, carried out by the firm IQAir.

The main sources of contamination are vehicles, agricultural burning, unpaved streets, clandestine tyre burning as well as industry and commerce.

What can be done to improve air quality in Mexicali?

The State Environment will intensify the reviews of industries in order to detect irregularities and initiate legal actions against those that do not comply with environmental regulations. So far this year there have been more than 100 inspections and 10 closures by the state to industries for various faults in environmental matters, it is hoped that the figure will increase next year by intensifying the work.

Experts believe that for a city of its size, Mexicali needs many more air quality monitors. The Baja California Secretariat for Environmental Protection lacks mobile atmospheric analysis equipment to measure emissions from factories. The state government has only four air monitoring stations operating in all of Mexicali.

Not all pollution in the border region comes from factories. Other strategies to reduce air pollution would also help, such as paving more dirt roads, reforming the ineffective smog control system and improving police surveillance to stop the illegal burning of garbage and agricultural fields.

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

As the world warms and the population increases, vehicle engines continue to emit dirty emissions, and half the world does not have access to clean fuels or technologies (for example, stoves and lamps). The very air we breathe is becoming dangerously polluted: Nine out of ten people are now breathing polluted air, which kills an estimated 7 million people each year. The health effects of air pollution are serious: a third of deaths from strokes, lung cancer and heart disease are due to air pollution. It is an effect equivalent to that of smoking tobacco and is much more serious than, for example, the effects of ingesting too much salt. The lower the levels of air pollution, the better the cardiovascular and respiratory health of the population, both in the long and short term.