Air pollutants and its impact

Air pollution caused by atmospheric contaminants is one of the most critical and complex environmental problems we face today, both because of its global reach and the harmful effects it causes on human health, ecosystems, and materials. These contaminants can be primary, meaning they are emitted directly from a specific source, such as gases produced by vehicle combustion, industrial emissions, or forest fires. Additionally, there are secondary contaminants formed through chemical reactions between primary pollutants and other atmospheric components influenced by sunlight.

This article examines the main atmospheric pollutants to which we are exposed and their origin, the effects they cause on our health and the environment, and finally reviews current regulations and solutions to halt their spread, such as air monitoring, which not only identifies their presence but measures their levels for precise control, offering the best chance to keep breathing clean air.

What are atmospheric pollutants?

Definition and general characteristics

The atmosphere accumulates multiple substances with chemical, physical, or biological properties that, when present at high concentrations or in unnatural forms, are classified as atmospheric pollutants. These compounds alter the chemical composition of the air and compromise its quality, generating adverse impacts on human wellbeing and ecosystem balance.

Classification: primary vs secondary

Atmospheric pollutants are classified into two main categories based on their origin:

• Primary pollutants: emitted directly from an identifiable source. Key examples include:
  • Nitrogen oxides (NO_x) and carbon monoxide (CO)The carbon monoxide (CO) is an invisible gas (colorless and odorless) that, at the same time, is a silent killer because in just a few minutes it exhibits ...
    Read more generated by internal combustion engines.
  • Particulate matter (PM₁₀ and PM_2.5) originating from industrial processes, construction, and biomass burning.
  • Volatile organic compounds (VOCs) released by solvents, paints, and agricultural activities.

• Secondary pollutants: not emitted directly, but formed in the atmosphere through chemical reactions between primary pollutants and other air components such as water vapor or oxygen. These reactions are usually catalyzed by sunlight. An example is tropospheric ozoneTropospheric ozone (O3) or ground-level ozone is a gas found in the lowest layer of the Earth's atmosphere, the troposphere, which extends up to 10 kilomet...
  Read more (O₃), a key component of photochemical smogSmog, beyond that dense fog Smog is a mixture of air pollutants that accumulate in the atmosphere, especially in urban areas. This phenomenon is character...
  Read more, formed by the interaction of NO_x and VOCs under strong sunlight.

Main atmospheric pollutants

The most common and harmful atmospheric pollutants affecting public health and ecosystems include:

• Carbon dioxide (CO₂)Carbon dioxide (CO2) is a gas that occurs naturally in the atmosphere and plays a crucial role in the life processes of the planet. This gas, also known as...
  Read more: a greenhouse gas that contributes to global warming.
• Carbon monoxide (CO): a toxic gas that impairs the body’s ability to transport oxygen.
• Nitrogen oxides (NO_x) and sulfur oxides (SO_x): irritant gases causing respiratory issues. Produced by burning fuels, they react with oxygen and water vapor to form acids (sulfuric and nitric) transported by rain, hence the term acid rain.
• Particulate matter (PM)Atmospheric particulate matter are microscopic elements suspended in the air, consisting of solid and liquid substances. They have a wide range of sizes an...
  Read more: tiny solid or liquid particles capable of penetrating deep into the lungs.
• Volatile organic compounds (VOCs): a broad category of chemical substances contributing to smog or grey haze mixed with smoke and suspended dust.

Sources of atmospheric pollutants

Atmospheric pollutants can be of anthropogenic origin (produced by human activities) or of natural origin (derived from natural environmental processes).

Besides their origin, sources of atmospheric pollutants differ in their characteristics.

• Point sources: stationary and localized, such as power plants and industries.
• Mobile sources: related to transport and internal combustion engine vehicles.
• Area sources: dispersed activities like agriculture or use of household products.
• Natural or biogenic sources: natural processes such as volcanic eruptions, forest fires, or vegetation emissions.

Considering possible sources of atmospheric pollutants, we now analyse the main ones:

Industrial and energy emissions

Both industrial activities and energy generation are the main contributors to a large proportion of atmospheric pollutants. They come from the burning of fossil fuels (coal, oil, natural gas) in power plants and factories. This results in significant atmospheric pollutants including nitrogen oxides, sulfur dioxide, carbon monoxide, particulate matter, volatile organic compounds, and heavy metals like mercury. Together, these pollutants affect air, water, and soil quality and are linked to the development of respiratory diseases, cardiovascular problems, and cancer.

Traffic and transport

The transport sector, dominated by vehicles with internal combustion engines, is a significant source of atmospheric pollutant emissions. Key compounds released include nitrogen oxides (NO_x), carbon monoxide (CO), carbon dioxide (CO₂), particulate matter, and volatile organic compounds (VOCs). These emissions not only degrade air qualityAir quality refers to the state of the air we breathe and its composition in terms of pollutants present in the atmosphere. It is considered good when poll...
Read more but position traffic as one of the main sources of atmospheric pollution in urban environments.

In countries with higher economic development, traffic can contribute between 30% and 90% of total emissions of certain transport-related pollutants. This variability depends on factors like the vehicle fleet, environmental policies, and urban infrastructure.

Agriculture, domestic and natural sources (dust, biogenic)

Intensive agriculture has greatly increased atmospheric pollutant emissions due to excessive use of nitrogen and phosphorus fertilizers, pesticides, and poor organic waste management.

These processes release ammonia (NH₃), nitrogen oxides (NO_x), methane (CH₄)Methane, known chemically as CH₄, is a gas that is harmful to the atmosphere and to living beings because it has a high heat-trapping capacity. For this ...
Read more, and particulate matter, contributing both to air pollution and to the formation of secondary pollutants and greenhouse gasesWhile the concentration of carbon dioxide (CO2) in the atmosphere has been steadily and rapidly increasing in recent decades, in May 2025, CO2 surpassed 43...
Read more.

On the domestic front, atmospheric pollution arises from fuel use (cooking and heating), use of cleaning products, paints, and construction materials that release volatile organic compounds, and from biological pollutants (mites, mold).

Natural sources of atmospheric pollutants come from volcanic eruptions, forest fires, dust storms, biological activity of microorganisms, vegetation, and organic matter decomposition.

These sources can release large amounts of sulfur dioxide (SO₂), carbon monoxide (CO), nitrogen oxides (NO_x), particulate matter, hydrocarbons, and methane (CH₄).

Although emissions from natural sources can exceed those of anthropogenic origin in volume, the latter usually have a greater environmental impact; especially in urban and industrial areas due to the high concentration of pollutants they generate.

In summary, the different sources of atmospheric pollution, both human and natural, contribute to the presence of a wide variety of harmful substances in the atmosphere, affecting public health, ecosystems, and the global climate.

Measurement and monitoring of atmospheric pollutants

Regular monitoring is crucial to maintaining air quality. It is the way to properly identify atmospheric pollutants present and the levels at which they occur and to which we are exposed. Measurement and monitoring of atmospheric pollutants constitute the scientific basis for understanding the air quality we breathe. This process involves the precise and continuous detection of pollutant substances in the atmosphere.

Environmental monitoring not only identifies air pollution levels but also provides essential information for decision-making. Based on the data provided by environmental sensor networks, effective strategies for controlling and preventing air pollution are implemented to protect health. Additionally, real-time and continuous data allows for mapping pollutant evolution, anticipating critical episodes, and evaluating the effectiveness of adopted measures to promote a safer and healthier environment.

To achieve this, advanced technologies are employed, including:

Traditional sampling methods

Although the measurement of atmospheric pollutants has evolved, traditional methods remain a reliable source for obtaining precise data. Generally, they collect representative air samples to be later analysed in a laboratory to identify atmospheric pollutants and their concentrations. The main traditional methods are:

• Gravimetric sampling: used to measure particulate matter (PM₁₀, PM_2.5), based on passing a defined volume of air through a specific filter (quartz, fiberglass or Teflon). The weight difference of the filter before and after determines the mass and thus the particle concentration. It remains widely used due to its high precision.
• Passive sampling: used to capture gaseous pollutants through absorbent tubes or discs exposed to the air for a set period. The material is then analysed in a laboratory to quantify present contaminants. This is a low-cost technique used for long-term measurements.
• Spot or extractive sampling: individual samples are collected at a given time to analyse temporal or spatial variations in atmospheric pollution. Gaseous pollutants are captured using an extractive method that draws air through a collector equipped with measurement instruments.

Real-time environmental sensor networks

Atmospheric pollutant monitoring has undergone a revolution thanks to the integration of real-time environmental sensor networks. These networks, composed of interconnected and strategically distributed devices, allow continuous and detailed measurement of air quality in urban, industrial, and rural environments, providing hyperlocal and updated data on atmospheric pollutant presence.

Atmospheric pollutant sensors collect air samples and detect harmful substances through physical or chemical processes. The main types of sensors operate through:

• Electrochemical sensors: detect gases such as carbon monoxide (CO), nitrogen dioxide (NO₂)Nitrogen dioxide (NO2) is a harmful gas whose presence in the atmosphere is mainly due to the use of fossil fuels in combustion vehicles and industrial act...
  Read more and ozone (O₃) through chemical reactions that generate electrical signals proportional to the pollutant concentration.
• Optical sensors (light scattering): used to measure particulate matter (PM₁, PM_2.5, PM₁₀), employing lasers and photodetectors to quantify the amount of particles present in the air.
• Infrared sensors: utilise the selective absorption of infrared radiation by certain gases to determine their atmospheric concentration.

Consequently, real-time environmental sensor networks represent a cutting-edge technological tool for monitoring atmospheric pollutants, providing precise and accessible information that facilitates effective decision-making for environmental management and public health protection.

Data analysis and visualization platforms

Real-time environmental sensor networks used for the measurement and control of atmospheric pollutants are based on IoT technologies connected to software for pollutant and emission analysis. Each sensor collects, processes, and transmits data to centralized or cloud platforms. Through the analysis of the data gathered by these sensors, it is possible to:

• Visualise and analyse data in real time: Data is presented on dashboards accessible from any connected device, facilitating immediate decision-making during air pollution episodes.
• Dense spatial coverage: Unlike traditional stations, low-cost environmental sensors can be deployed in greater numbers, covering large areas and detecting local variations in atmospheric pollutants.
• Early alerts and rapid response: Continuous monitoring enables the swift detection of anomalies, such as pollution peaks, allowing activation of emergency protocols or immediate communication to the public.

Effects of atmospheric pollutants on health and the environment

Exposure to atmospheric pollutants can cause serious health problems, such as respiratory and cardiovascular diseases, and even the development of cancer. Moreover, they contribute to climate change and ecosystem degradation, threatening the survival of many species and their habitats. These compounds, present in the air due to human and industrial activities, generate far-reaching impacts.

Respiratory and cardiovascular impacts

Inhalation of atmospheric pollutants such as particulate matter (PM_2.5 and PM₁₀), nitrogen dioxide (NO₂), ozone (O₃), and sulfur dioxide (SO₂) is directly linked to numerous adverse effects on human health:

• Respiratory diseases: Exposure to fine particles and irritating gases can cause or worsen asthma and chronic bronchitis. Ultimately, it leads to illnesses such as emphysema, chronic obstructive pulmonary disease (COPD), and lung cancer. Children, elderly, and those with pre-existing conditions are especially vulnerable. This results in an increase in emergency visits and hospitalisations due to respiratory symptoms, as well as reduced lung function and higher susceptibility to infections.
• Cardiovascular diseases: Ultrafine particlesAt first glance, the air around us may seem clean, but beware, it hides an almost imperceptible danger: ultrafine particles (UFP). With a size so small the...
  Read more can cross the lung barrier and enter the bloodstream causing systemic inflammation, endothelial dysfunction, and atherosclerosis. This increases the risk of myocardial infarction, strokes, arrhythmias, and heart failure. It is estimated that between 40% and 80% of deaths attributable to air pollution are cardiovascular in origin.

• Cancer and premature mortality: Chronic exposure to atmospheric pollutants such as benzene, fine particles, and ozone is associated with a higher risk of lung cancer and premature death. In Europe, air pollution causes hundreds of thousands of premature deaths annually.

“An analysis in 652 cities shows an increased short-term mortality risk after exposure even to small concentrations of urban air pollution. On average, an increase of 10 micrograms/m³ in inhalable (PM₁₀) and fine (PM_2.5) particles is associated with a 0.44% and 0.68% increase in mortality, respectively.”

Damage to the environment and biodiversity

Atmospheric pollutants not only affect human health but also profoundly alter ecosystems:

• Acidification and eutrophication: Nitrogen oxides, sulfur dioxide, and ammonia in soils and water bodies cause acidification and nutrient overload, disrupting the balance of ecosystem species and reducing biodiversity.

• Damage to vegetation: Tropospheric ozone and other pollutants reduce photosynthesis, damage plant tissues, and decrease crop and forest yields. This affects agricultural and forestry productivity, as well as the capacity of ecosystems to act as carbon sinks.

• Habitat and species disruption: Air pollution contributes to climate change, modifying rainfall patterns, temperature, and frequency of extreme events, which threatens the survival of many species and their natural habitats.

In the European Union, 73% of ecosystems exceed critical nitrogen eutrophication loads.

Associated social and economic costs

The impact of air pollution goes beyond health and environment, generating significant social and economic costs:

• Direct and indirect health costs: Including medical expenses, hospitalisations, pharmaceutical treatments, and loss of labour productivity due to illness and premature death.

• Loss of well-being and productivity: Pollution reduces quality of life, increases work absenteeism, and lowers productivity. According to ESADE Business School, each additional microgram of PM_2.5 per cubic metre can reduce real GDP by 0.8% annually in affected European regions.

• Macroeconomic impact: Total costs associated with air pollution in the EU range between 166 billion and 940 billion euros annually, representing between 3.5% and 6% of GDP, according to various estimates. Most of these costs are due to premature mortality and morbidity related to pollution.

• Environmental costs: Include soil degradation, loss of biodiversity, damage to infrastructure, and reduction of ecosystem services, negatively impacting sectors like agriculture, forestry, and tourism.

Overall, the effects of atmospheric pollutants constitute a multidimensional challenge requiring integrated responses from public health, environmental management, and economic policy.

In Europe, air pollution causes an average annual cost per inhabitant exceeding 1,250 euros and around 926 euros per person in urban areas in Spain.

Regulation and management of air pollutants

Regulation of air pollutants is key to protecting public health and the environment. At international, European and national levels, there are management rules and policies that set limits, objectives and strategies to reduce air pollution and control the emissions that cause atmospheric pollution.

Main rules and standards (EU, WHO, national)

The main regulations on air pollutants at international and national level are:

• European Union (EU): Directive 2024/2881, in force since December 2024, represents the most advanced legal framework. This regulation sets binding limit values and objectives for pollutants such as fine particles (PM_2.5, PM₁₀), nitrogen dioxide (NO₂) and ozone (O₃), progressively aligning European standards with the World Health Organization (WHO) guidelines defined in 2021. It also introduces alert thresholds, periodic reviews and the obligation to act in the event of risks of exceeding the limits.
• World Health Organization (WHO): its guidelines set reference values based on the latest scientific evidence, recommending even stricter limits to protect health, especially against fine particles and toxic gases.
• National regulation (Spain): Law 34/2007 and Royal Decree 102/2011 form the legal basis for the assessment and management of air quality in Spain, transposing European directives and establishing action plans and limit values for the main pollutants.

Emission management and control policies

The management of air pollution is structured through a set of coordinated strategies at national, regional and local level, with the aim of reducing emissions and protecting public health and the environment. These policies are based on three fundamental pillars:

• National and regional planning: Spain has the National Air Pollution Control Programme (PNCCA), which sets out sectoral measures to reduce emissions and ensure compliance with European commitments. In turn, the autonomous communities and municipalities develop specific plans to address episodes of high pollution and manage particularly vulnerable urban areas.
• Environmental management tools: the implementation of these policies relies on air quality monitoringControlling air quality is an essential task in order to enjoy optimal environmental conditions for healthy human development and to keep the environment i...
  Read more networksAir quality monitoring networks consist of an organised system of monitoring stations distributed across various locations to measure and assess air pollut...
  Read more, atmospheric simulation models and early warning systems. Current regulations promote the use of best available techniques (BAT), the transition to less polluting fuels and the active participation of citizens in the development and review of air quality plans.
• Regulatory review and updating: regulations are updated periodically to incorporate the latest scientific and technological advances. This process allows emission limits and control strategies to be adjusted in line with World Health Organization (WHO) recommendations and the evolution of recorded pollution levels.

Overall, the regulation and management of air pollutants constitute a dynamic, evidence-based system aimed at the continuous improvement of air quality and the protection of health and ecosystems. This comprehensive approach enables a more effective and adaptive response to current and future environmental challenges.

Strategies for reducing air pollutants

Reducing air pollutants requires a comprehensive approach that combines technological innovation, energy transition and changes in production and consumption habits. The most effective policies focus on tackling emission sources, promoting clean energy and increasing efficiency across all sectors.

Control technologies at source

The implementation of control technologies at source is essential to limit and reduce industrial and urban emissions that cause air pollution. Measures include filtration and purification systems in chimneys, catalytic converters in vehicles, and cleaner industrial processes. Many countries have strengthened regulations, setting stricter emission limits and promoting tax incentives for those who adopt clean technologies. Emission control in waste management and the circular economy also helps to reduce the release of pollutants.

Transition to clean energy and sustainable mobility

The transition to renewable energy sources (solar, wind and hydroelectric) is key to reducing dependence on fossil fuels and thus lowering the carbon footprintIn a world increasingly affected by climate change, understanding how our everyday actions contribute to its worsening has become essential. The carbon foo...
Read more. Governments have increased investment in renewables and promoted electric mobility through subsidies and the expansion of charging infrastructure. In addition, public transport, active mobility (cycling, walking) and the restriction of polluting vehicles in urban areas are encouraged through the introduction of low emission zones, achieving a substantial improvement in air quality.

Improvement of industrial processes and efficiency

Energy efficiency in industry and buildings has been enhanced through regulations requiring more rigorous standards and the use of advanced technologies. Energy efficiency programmes, building refurbishment and the optimisation of industrial processes make it possible to reduce energy consumption and associated emissions. These strategies, together with sustainable waste management, are part of national and European plans to achieve the emission reduction targets set for 2030 and 2050.

Frequently asked questions about air pollutants

Which air pollutants are the most harmful?

The most harmful air pollutants for human health are:

• Particulate matter (PM₁₀ and PM_2.5): especially dangerous because they can penetrate deep into the lungs and, in the case of PM_2.5, reach the bloodstream. Exposure is linked to respiratory and cardiovascular diseases, lung cancer and premature mortality.
• Tropospheric ozone (O₃): a powerful respiratory irritant that worsens asthma, reduces lung function and can increase mortality from cardiovascular and respiratory diseases.

• Nitrogen dioxide (NO₂): mainly from traffic and industrial combustion. Inhalation causes inflammation of the airways, reduced lung development in children and worsens conditions such as asthma and bronchitis.
• Sulphur dioxide (SO₂)Sulphur dioxide (SO2) is a colourless gas with a pungent odour that causes an irritating sensation similar to shortness of breath. Its origin is anthropoge...
  Read more: generated by the burning of fossil fuels, it can cause irritation, lung inflammation and asthma attacks, as well as contributing to the formation of acid rain.
• Carbon monoxide (CO): interferes with the transport of oxygen in the blood, affecting vital organs and the nervous system, and can be fatal at high concentrations.
• Volatile organic compounds such as benzene and benzo(a)pyrene: carcinogenic and affect the immune and nervous systems.
• Heavy metals (lead, mercury, cadmium): emitted by industry and traffic, they have neurotoxic effects and can cause kidney and cardiovascular damage.

These pollutants, even at low concentrations, are associated with an increase in chronic diseases and mortality, especially in children, the elderly and vulnerable people.

How does weather influence their dispersion?

Weather plays a fundamental role in the dispersion, transport and concentration of air pollutants. The main meteorological factors influencing this process are wind (speed and direction), as it is a horizontal dispersal agent for pollutants; atmospheric stability, which allows little vertical mixing to disperse pollutants; temperature, which favours volatilisation and vertical dispersion of pollutants; solar radiation, which helps the formation of secondary air pollutants; precipitation, which cleans the atmosphere by helping to remove particulate and soluble gaseous pollutants; and humidity, which, at high levels, enhances the formation of secondary pollutants.

What sensors do I need for reliable monitoring?

For reliable air quality monitoring, it is essential to select sensors capable of measuring the main pollutants and environmental parameters that affect health and the environment. The technical choice for a robust system should include environmental sensors that allow real-time detection and accurately measure the following key parameters:

• PM₁, PM_2.5 and PM₁₀: microscopic particles suspended in the air, associated with respiratory and cardiovascular problems.
• Carbon dioxide (CO₂): an indicator of ventilation and indoor occupancy, as well as an indirect pollutant.
• Carbon monoxide (CO): a toxic gas that is lethal at high concentrations.
• Ozone (O₃), nitrogen dioxide (NO₂) and sulphur dioxide (SO₂): important due to their toxicity outdoors and in urban areas.
• Ammonia (NH₃), formaldehyde (HCHO/CH₂O) and other specific compounds depending on the potential source of pollution.
• Volatile organic compounds (VOCs): a wide range of chemical substances present in building materials, cleaning products, combustion, etc.
• Temperature, humidity and atmospheric pressure: essential for correctly interpreting pollution data and calibrating sensors.

How do I interpret air quality indices?

The air quality index (AQI)The air we breathe is essential to life. Good air quality makes us feel better and protects our health. The Air Quality Index (AQI) measures the pollutants...
Read more is a tool that translates the concentrations of the main air pollutants into a numerical value and an easily interpreted category (numerical scale and colour coding) for the public. Its aim is to clearly inform about the level of pollution and the associated health risks.

The AQI is based on the concentrations of several key pollutants: particulate matter (PM₁₀ and PM_2.5), ozone (O₃), nitrogen dioxide (NO₂), sulphur dioxide (SO₂).

For each pollutant, a sub-index is calculated according to its concentration, and the final AQI value corresponds to the pollutant with the worst quality at that moment. This means that if a single pollutant exceeds the established limits, the index reflects that risk, even if the others are within acceptable values. The higher the AQI value, the darker and higher the colour and, consequently, the worse the air quality and the greater the health risk.

Pollutant	Level index (based on pollutant concentrations in µg/m3)
	Good	Fairly good	Moderate	Unfavourable	Very unfavourable	Extremely unfavourable
	(0-25)	(26-50)	(51-75)	(76-100)	(101-125)	(126-200)
PM2.5 (24h)	0-10	10-20	20-25	25-50	50-75	75-800
PM10 (24h)	0-20	20-40	40-50	50-100	100-150	150-1200
NO2	0-40	40-90	90-120	120-230	230-340	340-1000
O3	0-50	50-100	100-130	130-240	240-380	380-800
SO2	0-100	100-200	200-350	350-500	500-750	750-1250

In addition, authorities usually accompany AQI reports with specific recommendations for the general population and for more vulnerable people, such as avoiding outdoor activities or taking extra precautions.

What actions can citizens take to help reduce them?

Active citizen participation is key to reducing air pollution and improving air quality, both in urban and rural areas. When these actions are adopted collectively and consistently, their impact can be profound, both locally and globally.

The main actions that citizens can take to improve the air they breathe are:

• Sustainable mobility: by reducing the use of private cars and prioritising public transport, cycling or walking, which significantly reduce emissions of nitrogen oxides, fine particles and other pollutants. Car sharing and rationalising car use also help to reduce traffic and thus air pollution. Efficient driving that avoids sudden acceleration and braking, respecting speed limits and switching off the engine during long stops generally reduces fuel consumption. Finally, choosing less polluting vehicles helps to reduce the environmental footprint of transport.
• Energy efficiency at home: through the responsible use of heating and air conditioning, as adjusting the thermostat reduces energy consumption. Proper maintenance of boilers, air conditioning systems and appliances ensures their efficiency and reduces emissions. Opting for renewable sources and sustainable technologies at home is an investment in environmental health.
• Responsible consumption and waste management: buying local, durable products with less packaging reduces air pollution from production and transport. In addition, properly separating waste and avoiding burning rubbish or plant remains prevents the emission of particles and toxic gases.
• Green spaces and healthy urban planning: contributing to, providing and demanding well-maintained urban trees and gardens improves air quality, as green areas absorb pollutants and generate oxygen. Achieving this requires the support of sustainable urban policies and citizen initiatives that promote pedestrian zones, traffic restrictions and efficient public transport for collective well-being.
• Environmental education and awareness: staying informed, sharing knowledge and actively participating in community projects helps to understand the effects of air pollution. In addition, spreading good practices multiplies the positive impact of individual actions and strengthens the social fabric.

Every action counts. Adopting sustainable habits not only improves air quality, but also protects public health, mitigates climate change and transforms our cities into more liveable and resilient spaces. The solution is in our hands.

Conclusion

Air pollution is one of the most urgent environmental challenges of our time due to its impact on human health, ecosystems and the climate. In the face of this reality, environmental monitoring and management have become key tools to diagnose, prevent and reduce the emission of air pollutants. However, the effectiveness of these actions depends on a shared vision and collaboration among all stakeholders.

International cooperation is essential to establish common standards, share clean technologies and coordinate policies that transcend borders. At the same time, technological innovation offers increasingly precise and efficient solutions to measure air quality, optimise industrial processes and promote more sustainable mobility. But the commitment of every individual, company and institution is also crucial: from adopting responsible habits to demanding more ambitious, transparent and environmentally committed public policies.

Reversing air pollution is not just a technical goal, but an ethical imperative. Through a comprehensive approach, based on science, equity and sustainability, we can ensure a healthier and fairer environment. Clean air should not be a privilege, but a universal right that we must protect today to ensure our well-being and that of future generations.