Air Pollution Crisis In Mexico: Why It's A Problem

Air pollution is a pressing issue in Mexico, causing about 5.9% of all deaths in the country and severely impacting citizens' health, natural beauty, and modernity. Mexico City, in particular, has been dubbed the most polluted city in the world due to various factors, including industrialisation, urbanisation, population growth, vehicle emissions, and geographical constraints. The Mexican government has implemented plans to address the problem, but the progress has been insufficient, and the city continues to struggle with poor air quality. With the health of its residents at stake, Mexico City serves as a stark example of the urgent need to tackle air pollution and its detrimental effects.

Population growth, industrialisation, and vehicle emissions

Mexico City's air pollution has been a concern for its population and health officials for decades. In the 20th century, the city underwent rapid population growth, industrialisation, and urbanisation. The population of the metropolitan area of the valley of Mexico, also called Greater Mexico City, grew substantially from 3.1 million in the 1950s to 14 million in the 1980s and 20 million by 2015. This population boom occurred mainly due to migrants seeking better opportunities, which in turn led to the industrialisation of the city. The increase in manpower and human activities resulted in severely poor air quality.

Industrial growth was responsible for emitting over 11,000 tons of waste material into the atmosphere every day. The economy boomed, and the proliferation of vehicles increased. In 1980, there were 124 cars and light-duty trucks per 1,000 residents, and by 2010, this number had increased to 267. The topography of Mexico City did not favour its industrialisation, as it is located in a basin where air pollutants tend to be trapped. The interaction of nitrogen oxides (NOx) with volatile organic compounds (VOCs) and ultraviolet (UV) radiation from the sun accelerates the formation of ground-level ozone, a major air pollutant.

Vehicle emissions in Mexico have been historically higher than in the United States. This is linked to outdated vehicle technologies, with studies showing that outdated vehicle technology raises overall CO, HC, and NO emissions. In the 1980s, the cars in Mexico City were of poor quality and ran on very toxic fuel. The automatic air-quality monitoring network, established in the late 1980s, revealed high concentrations of all criteria pollutants, including lead, carbon monoxide, nitrogen dioxide, sulphur dioxide, ozone, and particulate matter (PM).

To address air pollution, the Mexican government has implemented various measures, including the ""Hoy No Circula" policy, which restricts vehicles from circulating based on their emissions performance. However, the effectiveness of such policies has been questioned. Other initiatives include the removal of lead from gasoline, the implementation of catalytic converters, and the reformulation of liquefied petroleum gas for heating and cooking.

Inadequate government policies and lack of federal support

Mexico has ratified the Paris Agreement, but it has yet to set a net-zero target. According to the Climate Action Tracker (CAT), Mexico's efforts to combat climate change are insufficient due to a lack of concrete decarbonisation plans. While GHG-related policies do not directly address air pollution, the Mexican government's approach to this global issue reflects its attitude toward more localised environmental concerns.

The Mexican government has faced criticism for its inadequate policies and lack of federal support for local initiatives. For example, the federal government has not provided financial and political backing for local government environmental policies. This lack of support has hindered progress in addressing air pollution, which is a pressing national issue.

Mexico City, in particular, has struggled with air pollution for decades. The city's high altitude of 7382 feet above sea level results in oxygen levels that are 25% lower than at sea level. In addition, carbon-based fuels do not combust completely at this altitude, contributing to poor air quality. The city's basin-like topography also traps air pollutants, further exacerbating the problem.

Population growth, urbanisation, and industrial activities have significantly contributed to air pollution in Mexico City. The number of vehicles has increased, and the city's public transportation system struggles to meet the demands of its growing population. Many residents rely on older, more polluting cars, with pre-1985 vehicles accounting for about 70% of car pollution. The government has implemented vehicular restrictions to reduce emissions, but the public transportation system is inadequate and overcrowded, leading to a reliance on private vehicles.

Mexico City's air quality still needs improvement, despite the significant progress made since the 1990s. The government has implemented plans to reduce emission levels, including citizen participation, increasing green areas, and promoting bicycle accessibility. However, the city still falls short of the internationally recommended ratio of green areas to urbanised spaces, contributing to heat islands and particle resuspension.

In summary, inadequate government policies and a lack of federal support have contributed to the persistence of air pollution in Mexico, particularly in Mexico City. While the government has recognised the problem and taken some action, more comprehensive and aggressive policies are needed to address the root causes of air pollution effectively.

Poor public transport infrastructure and older vehicles

Mexico City's air pollution is caused by a multitude of factors, including poor public transport infrastructure and older vehicles. The city has a vast public transportation system, with 2,000 buses, 80,000 taxis, and 30,000 microbuses. However, this system is incredibly overcrowded and inadequate for the millions of residents who rely on it. The inefficiency of public transportation in Mexico City has led to residents owning 3.5 million vehicles, which are a major source of pollution.

The proliferation of private vehicles, especially older models, has resulted in an unchecked release of harmful pollutants. Approximately 30% of the registered vehicles in Mexico are over 20 years old. These older cars are a significant contributor to air pollution, as they often lack modern emissions systems and run on toxic fuel. In fact, it is estimated that about 70% of car pollution is caused by pre-1985 vehicles.

The inadequate public transportation system in Mexico City is a result of the city's rapid population growth and urbanisation. The metropolitan area experienced a substantial increase in population from 3.1 million in the 1950s to over 20 million today. This rapid growth has led to overcrowding, congested streets, and a lack of adequate infrastructure.

To address the issue of air pollution caused by older vehicles and poor public transport infrastructure, the Mexican government has implemented several plans. These plans include restrictions on vehicular emissions, an increase in green areas, and expanded bicycle accessibility. However, the implementation of these plans has been challenging due to the lack of financial and political backing from the federal government.

The impact of air pollution on the health of Mexico City's residents is dire. It is estimated that about one in 17 deaths in the country is caused by air pollution. Short-term effects include allergies, respiratory issues, and skin problems, while long-term exposure has been linked to more severe conditions like asthma, chronic obstructive pulmonary disease, and cognitive decline in children.

Household use of firewood and charcoal

Air pollution is a significant issue in Mexico, causing about one in 17 (5.9%) of all deaths in the country. According to the World Bank, outdoor air pollution in towns and cities is responsible for nearly 20,000 deaths annually, while household air pollution, primarily from cooking with wood and other solid fuels in rural areas, accounts for 13,000 deaths.

The use of firewood and charcoal for household cooking and heating is prevalent in Mexico, particularly in rural communities. Approximately 16 million Mexicans, or more than one in eight people, rely primarily on firewood or charcoal for cooking, and many households use them as secondary fuels. This practice contributes significantly to indoor air pollution and can have severe health consequences.

The World Health Organization (WHO) has set a limit for average outdoor ambient air pollution of 10 micrograms (µg) of PM2.5 (particulate matter with a diameter of less than 2.5 micrometres) per cubic metre of air (10 µg/m3). However, the average concentrations of PM2.5 in Mexico City are about 25 µg/m3, and even higher in other cities such as Puebla, Toluca, and Monterrey.

The use of firewood and charcoal for cooking results in high levels of PM2.5 exposure for those doing the cooking. Concentrations of PM2.5 in the air they breathe can be 11-26 times higher than the WHO recommendation. This puts them at risk of respiratory problems and other health issues. Simply replacing open fires and traditional stoves with improved cookstoves that have chimneys can reduce this exposure by half, but the average concentration of PM2.5 remains about 80 µg/m3, still eight times the recommended limit.

To achieve more significant improvements, households need to transition to cleaner energy sources such as liquefied petroleum gas (LPG). Converting all households to LPG is estimated to save 3,400 lives each year and provide annual benefits of nearly 40 billion Pesos, despite the high initial cost of 16 billion Pesos. This transition is crucial, especially for rural communities, to reduce the health risks associated with indoor air pollution caused by the household use of firewood and charcoal.

Climate change and wildfires

Mexico's location and climate make it vulnerable to dry conditions and periods. The country experienced one of its most severe droughts in decades in 2021, with nearly 85% of the country categorised as "dangerously dry". This extreme drought, combined with deforestation and land conversion, sparked 6,224 wildfires between January and June of 2021.

Climate change has played a significant role in the Mexico wildfires of 2021. Global warming has deprived water and dried up vegetation, creating the ideal fuel for fires to burn. It has also altered the nature of wildfires, with wildfire seasons becoming longer, more intense, and spreading faster. Warmer nighttime temperatures allow fire activity to persist overnight, and the combination of fuel build-up and warmer, drier conditions increases the potential for extreme fires.

The effects of global warming are evident in Mexico, with larger and more intense fires producing suffocating smoke that can spread further and affect more people, particularly those with respiratory issues. Wildfire smoke adds to the already poor air quality in Mexico, driven by emissions from fossil fuel-powered vehicles and power plants.

The Mexican government has been criticised for its insufficient ambition to fight climate change and its lack of a concrete decarbonisation plan. While the government has several active plans to reduce emission levels, these require citizen participation, vehicular restrictions, increased green areas, and expanded bicycle accessibility.

Deforestation in Mexico, perpetrated by poor artisanal loggers, poor farming communities, and drug trafficking organisations, further exacerbates global warming and wildfires by reducing carbon and water absorption. The slow pace of the government's reforestation program has not significantly increased carbon capture in Mexico.

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